Resistive current measurement device and method

Abstract

A resistive current measurement device comprises: a substrate comprising a first conductive layer and a second conductive layer that is separate from the first conductive layer; a plurality of resistors arranged at the substrate, wherein each resistor of the plurality of resistors is connected between the first conductive layer and the second conductive layer; and a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminals are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

Description

[0001] RESISTIVE CURRENT MEASUREMENT DEVICE AND METHOD

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to a resistive current measurement device, a current measurement arrangement, a transistor test setup, a method for manufacturing a resistive current measurement device and a method for measuring a current.

[0004] BACKGROUND

[0005] Electrical current may be measured by driving the current through a resistor (shunt) and measuring a voltage drop across the resistor that is caused by the current flowing through the resistor, in accordance with Ohm’s law. In steady state, e.g., when a constant direct current flows through the resistor, the measurement may be rather simple. However, in situations when the current through the resistor changes dynamically, for example when a switch controlling the current is being turned on or turned off, an inductance and a capacitance of circuit elements come into play and may impact the measurement. Since the resistor used for measuring current itself can have such adverse effects, it may also introduce a certain inductance and / or capacitance into the circuit.

[0006] One example of such a dynamic situation is the characterization of power transistors, where the dynamic behavior of the transistor during a switching transient is investigated. The faster the switching speed of a transistor, the steeper a rising and / or falling edge current through the transistor and voltage blocked by the transistor. In particular steep current edges may result in overshooting voltage spikes due to parasitic stray inductance in the load current path. Furthermore, parasitic stray inductance and / or capacitance form parasitic oscillation circuits, that may be triggered during a switching transient. In order to correctly measure switching transients including parasitic oscillations, a bandwidth of the shunt has to be sufficiently large for the intended measurement case.

[0007] In addition, in high power applications, where voltages of several hundred volts and currents of several hundred amperes may be switched by transistors, a power rating of the shunt has to be sufficiently large so that the resistor can withstand the energy dissipation that is inevitably caused during the current flow. For increased power rating, larger sizes of resistors may be used. However, with increasing the size of the resistor, parasitic inductance and capacitance values may also increase significantly.

[0008] It is one objective of the present disclosure to improve current measurement with a resistive current measurement device.

[0009] SUMMARY

[0010] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key factors or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject-matter.

[0011] In some implementations a resistive current measurement device comprises: a substrate comprising a first conductive layer and a second conductive layer that is separate from the first conductive layer; a plurality of resistors arranged at the substrate, wherein each resistor of the plurality of resistors is connected between the first conductive layer and the second conductive layer; and a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminals are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

[0012] In some implementations, a method for manufacturing a resistive current measurement device includes the steps of:

[0013] Providing a substrate comprising a first conductive layer and a second conductive layer; Arranging a plurality of resistors at the substrate,

[0014] Electrically connecting a first terminal of each resistor of the plurality with the first conductive layer, Electrically connecting a second terminal of each resistor of the plurality with the second conductive layer; and

[0015] Providing a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminal are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

[0016] In some implementations, a method for measuring a current in a connection between a first circuit node and a second circuit node of an electrical circuit includes the steps of: Connecting a resistive current measurement device according to implementations described herein between the first circuit node and the second circuit node;

[0017] Connecting a voltage measurement device to the first measurement terminal and the second measurement terminal;

[0018] Driving the current to be measured through the resistive current measurement device; and Determining a voltage across the resistive current measurement device with the voltage measurement device.

[0019] In some implementations, a current measurement arrangement comprises: a resistive current measurement device according to implementations described herein, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal.

[0020] In some implementations, a transistor test setup configured for measuring a transient current response of a transistor under test comprises: a power source, a first load terminal connected to a first terminal of the power source and configured to be connected to a first transistor load terminal of the transistor under test, a second load terminal connected to a second terminal of the power source and configured to be connected to a second transistor load terminal of the transistor under test, a gate terminal configured to be connected to a transistor gate terminal of the transistor under test, a resistive current measurement device according to implementations described herein and connected between the power source and the first load terminal or the second load terminal, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal.

[0021] Those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

[0022] BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar or identical elements. The elements of the drawings are not necessarily to scale relative to each other. The features of the various illustrated examples can be combined unless they exclude each other.

[0024] Fig. 1 illustrates a cross section of a first embodiment of a resistive current measurement device;

[0025] Fig. 2 illustrates a cross section of a second embodiment of a resistive current measurement device;

[0026] Fig. 3 illustrates a cross section of a third embodiment of a resistive current measurement device;

[0027] Fig. 4 illustrates a top view of a fourth embodiment of a resistive current measurement device;

[0028] Fig. 5 illustrates a top view of a fifth embodiment of a resistive current measurement device; Fig. 6 illustrates a cross section of the fifth embodiment of a resistive current measurement device;

[0029] Fig. 7 illustrates a cross section of a sixth embodiment of a resistive current measurement device;

[0030] Fig. 8 shows a schematic diagram showing a frequency response of a resistive current measurement device;

[0031] Fig. 9 illustrates a schematic circuit diagram of an embodiment of a current measurement arrangement;

[0032] Fig. 10 illustrates a schematic circuit diagram of a test setup for measuring a transient current response of a transistor under test;

[0033] Fig. 11 A shows schematic current, voltage and power diagrams of a switch-on transient of a power transistor;

[0034] Fig. 11 B shows schematic current, voltage and power diagrams of a switch-off transient of a power transistor;

[0035] Fig. 12 illustrates an embodiment of a method for measuring a current;

[0036] Fig. 13 illustrates an embodiment of a method for manufacturing a resistive current measurement device.

[0037] DETAILED DESCRIPTION

[0038] The examples described herein provide a resistive current measurement device, a method for manufacturing such resistive current measurement device, a method for measuring a current, a current measurement arrangement and a test setup for measuring a transient current response of a transistor under test. In the following, details are set forth to provide a more thorough explanation of example implementations. However, it will be apparent to those skilled in the art that these implementations may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form or in a schematic view, rather than in detail, in order to avoid obscuring the implementations. In addition, features of the different implementations described hereinafter may be combined with each other, unless specifically noted otherwise.

[0039] It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.).

[0040] In implementations described herein or shown in the drawings, any direct electrical connection or coupling (e.g., any connection or coupling without additional intervening elements) may also be implemented by an indirect connection or coupling (e.g., a connection or coupling with one or more additional intervening elements, or vice versa) as long as the general purpose of the connection or coupling (e.g., to transmit a certain kind of signal or to transmit a certain kind of information) is essentially maintained. Features from different implementations may be combined to form further implementations. For example, variations or modifications described with respect to one of the implementations may also be applicable to other implementations unless noted to the contrary.

[0041] As used herein, the terms “substantially” and “approximately” mean “within reasonable tolerances of manufacturing and measurement.” For example, the terms “substantially” and “approximately” may be used herein to account for small manufacturing tolerances or other factors (e.g., within 5%) that are deemed acceptable in the industry without departing from the aspects of the implementations described herein. For example, a resistor with an approximate resistance value may practically have a resistance within 5% of the approximate resistance value. As another example, a signal with an approximate signal value may practically have a signal value within 5% of the approximate signal value.

[0042] In the present disclosure, expressions including ordinal numbers, such as “first”, “second”, and / or the like, may modify various elements. However, such elements are not limited by such expressions. For example, such expressions do not limit the sequence and / or importance of the elements. Instead, such expressions are used merely for the purpose of distinguishing an element from the other elements. For example, a first box and a second box indicate different boxes, although both are boxes. For further example, a first element could be termed a second element, and similarly, a second element could also be termed a first element without departing from the scope of the present disclosure.

[0043] Power transistors may be used as switches in applications such as switched-mode power supplies, power converters, motor drives, amplifiers, and others. This means that the power transistor is operated between two states, e.g., on or off. In the on state, the power transistor has a low resistance value so that a current can flow freely through the power transistor, and in the off state, the power transistor has high resistance so that it blocks current from flowing. The term “power transistor” shall be understood to include all kinds of transistors that may be used to switch a load current for driving a load. Examples are isolated gate bipolar transistors (IGBT), field-effect transistors (FET) and high electron mobility transistors (HEMT).

[0044] Power transistors may have three terminals: a first load terminal, a second load terminal and a control terminal. By applying a control voltage to the control terminal, which may be referenced to one of the load terminals, a conductive channel between the first load terminal and the second load terminal may be controlled, for example. In case of an IGBT, the load terminals may be referred to as emitter and collector, and in case of a FET or HEMT, the load terminals may be referred to as source and drain. The control terminal may be referred to as gate terminal for these transistors. Thus, by controlling a gate voltage between appropriate levels, the transistor may be switched between on state and off state.

[0045] When switching the transistor on or off, a switching transient occurs. During the switching transient, fast changes in the load current through the transistor and the voltage across the transistor’s load terminals may occur. A rate of change in the load current may be referred to as di / dt and a rate of change in the voltage across the transistor may be referred to as dv / dt in the following. For characterizing transistors, e.g., to determine their switching behavior in various operational conditions, such as at various load current, bus voltage, driving conditions, and / or temperature conditions, it is desired to measure the voltage across and current through the transistor at a high time resolution. Here, the voltage and current applied to the transistor may be up to several hundred or several thousand volts and several hundred or several thousand amperes.

[0046] The resistive current measurement device may be used to probe the current through the transistor at a high time resolution. For this, the resistive current measurement device may be arranged in series with the transistors load current path, such that the full load current that flows through the transistor at any given time also flows through the resistive current measurement device. This means, however, that the parasitic inductance of the resistive current measurement device may affect the load current, in particular at high di / dt values, and thereby distort the measurement result. At the same time, in order to be able to characterize the transistor at high switching speeds, a high bandwidth of the resistive current measurement device is desired. The bandwidth of a resistive current measurement device may be described by the following equation (1 ): fbw= R / 2nL (1 )

[0047] Here, fbw is the frequency of a current signal at which the transfer function of the resistive current measurement device deviates by about 3 dB from the DC (or low frequency) value, fbw may be referred to as the “3 dB point” and can also be referred to as the cut-off frequency of the device. R denotes the resistance of the resistive current measurement device and L denotes the stray inductance of the resistive current measurement device. According to equation (1 ), the bandwidth is proportional to the resistance and inverse proportional to the inductance of the resistive current measurement device. Hence, to increase the bandwidth, increasing the resistance R and decreasing the inductance L may be employed. However, energy dissipation in the resistive current measurement device must be considered at the same time, in particular at the high voltage and high current values that may be used for characterizing the transistor, which may otherwise destroy the device quickly.

[0048] A minimum bandwidth fbW, min that should be used for an accurate measurement for a given circuit and transistor may be estimated based on equation (2): fbw.min ~ 1.4 ■ fcir(2)

[0049] Here, fCir is a frequency that may occur in the circuit when switching the transistor on or off, and may be a rising edge frequency, falling edge frequency, or oscillation frequency of a resonant circuit formed by the various capacitances and inductances in the circuit. Example capacitances are the drain-source (or emitter-collector), drain-gate (or collector-gate), source-gate (or emitter-gate) capacitances of the transistor. Example inductances are the parasitic stray inductance of the resistive measurement device or of other wire connections in the circuit or the like. The rising / falling edge frequency fnse / faii may be calculated based on a rise time triSeor fall time tfaii of the current through the transistor when switching the transistor on (rise time) or off (fall time) according to equation (3): frise / fall ~ 0.35 ft-rise / fall (3)

[0050] Here, the rise time / fall time may be a time in which the load current through the transistor increases / decreases from about 10% to about 90% or vice versa of the quasi-static load current after switching the transistor on / off. Common values for frise / taii are in a range of a few MHz up to a few hundred MHz for power transistors. The oscillation frequency foscof a parasitic resonant circuit formed by an inductance Lpand a capacitance Cpmay be calculated using equation (4):

[0051] Oscillation frequencies may reach values of up to several GHz, depending on the given circuit and power transistor. As an example, if an oscillation frequency foscaccording to equation (4) has a value of 500 MHz, the minimum bandwidth of the resistive current measurement device for accurate measurement of the current changes during a switching transient may be calculated based on equation (2) as fbw,min=700 MHz.

[0052] Embodiments of the resistive current measurement device according to the present disclosure can withstand the high current pulse energies used in testing the transistor and at the same time provide for high bandwidth so that the measurements are essentially not disturbed by the resistive current measurement device. This is achieved by arranging a plurality of resistors on a substrate with two conductive layers. The resistors are connected in a parallel connection with respect to the conductive layers. Such parallel connection may reduce the overall inductance of the resistive current measurement device. Also, the load current can flow along a simple current path, without many deviations or splitting up into many current paths, which also keeps the inductance of the device low. At the same time, the energy dissipated in the device is distributed across many resistors, such that a power rating of the device satisfies the requirements of the application.

[0053] Fig. 1 illustrates a cross section of a first embodiment of a resistive current measurement device 100. The device 100 comprises a substrate 110 comprising a first conductive layer 112 and a second conductive layer 114 that is separate from the first conductive layerl 12.

[0054] The first conductive layer 112 and the second conductive layer 114 may comprise any conductive material, in particular metal materials, such as a copper (Cu) material, an aluminum (Al) material, a nickel (Ni) material, a tin (Sn) material, a zinc (Zn) material, a lead (Pb) material, a gold (Au) material, a silver (Ag) material, a manganese (Mg) material, a indium (In) material, a bismuth (Bi) material, an antimony (Sb) material, a palladium (Pd) material and / or alloys of these materials, such as a tin-silver-copper (Sn-Ag-Cu or SAC) alloy, for example. The aforementioned list of materials is merely illustrative and does not limit the scope of the present disclosure. Additionally, the conductive layers 112, 114 may include different sections that are formed from different conductive materials, for example to provide for varying electrical, mechanical, and / or thermodynamic properties in those sections. Further, a plurality of resistors 120 is arranged on the substrate 110. Each resistor 120 of the plurality of resistors 120 is connected between the first conductive layer 112 and the second conductive layer 114. That means, for example, a first end or first terminal of each resistor 120 is connected to the first conductive layer 112 and a second end or second terminal of each resistor 120 is connected to the second conductive layer 114. Each resistor 120 comprises a resistive element connected between the first and second ends or terminals.

[0055] In embodiments, the resistors 120 may be of a thick film resistor type, a thin film resistor type, a metal strip resistor type, or the like. The resistors 120 may comprise a conductive material that froms the resistive element, and comprise an isolating material, such as a ceramic, plastic or glass material, to support the conductive material.

[0056] In embodiments, different resistors 120 may be included in the plurality of resistors 120. For example, the different resistors 120 may have different ohmic values, different geometry, and / or are of a different type. This may be used, for example, to provide a specific current density distribution within the plurality of resistors 120.

[0057] In embodiments, some or all resistors 120 of the plurality of resistors 120 may have a first contact pad and a second contact pad and a resistive element connected between the first contact pad and the second contact pad.

[0058] In embodiments, the plurality of resistors 120 is provided as at least one group of resistors 120, each group of resistors 120 comprising at least two resistors 120 that are packed in close contact to each other. Here, in close contact may mean that the resistors 120 of a group are in physical contact with each other, or are only separated by a small gap that does not extend more than a size of one resistor 120, for example. Such gap may be filled by a material, such as an isolating material. For example, the resistors may be arranged in a stabilizing matrix formed from plastic, for example, which may hold the individual resistors in place.

[0059] In the embodiment shown in Fig. 1 , the substrate 110 is extending in a horizontal plane and the resistors 120 are stacked on each other, and the stack of resistors 120 extends in a vertical direction from the substrate 110. That is, the stack of resistors 120 extends perpendicular to the substrate 110. Portions of the first and second conductive layers 112, 114 may extend in the same vertical direction to cover the stack of resistors 120 and provide a direct electrical connection to the resistors 120. Alternatively or additionally, a connection structure or connection element may be used to provide for a low-ohmic connection between the resistors and the respective conductive layer 112, 114.

[0060] A first measurement terminal 132 is connected to the first conductive layer 112 and a second measurement terminal 134 is connected to the second conductive layer 114, wherein the first and second measurement terminal 132, 134 are configured for connecting a voltage measurement device VM (see Fig. 9 or 10) for measuring a voltage across the plurality of resistors 120.

[0061] In embodiments, there may be more than one stack of resistors 120 provided. For example, there may be three stacks of resistors arranged next to each other, each stack comprising two resistors or more.

[0062] In embodiments, the substrate 110 may include an isolating layer 116 (see Fig. 2, 3, 6 or 7). The isolating layer 116 may provide mechanical support for the conductive layers 112, 114 and the plurality of resistors 120. For example, the substrate 110 may be provided as a printed circuit board (PCB) or direct copper bonded (DCB) board. The isolating layer 116 may be formed from any isolating material that provides for sufficient electrical isolation between the conductive layers 112, 114 and for sufficient mechanical strength to support the device 100. Thus, the isolating layer 116 may be formed from a plastic material, a composite material, a ceramic material, a glass material, and / or from a mixture of those materials. In further embodiments, the isolating layer 116 may extend only in a portion of the device 100, such as, for example, in a portion where the plurality of resistors 120 is arranged. For example, the isolating layer 116 may span from the first conductive layer 112 to the second conductive layer 114, forming an isolated bridging element between the conductive layers across the plurality of resistors 120. In embodiments, when an isolating layer as described above is provided and at least one stack of resistors is provided, the at least one stack of resistors may be arranged on the isolating layer of the substrate. For example, the at least one stack of resistors may be fixed or attached to the isolating layer and extend from one surface of the isolating layer in a vertical direction perpendicular to the isolating layer.

[0063] Fig. 2 illustrates a cross section of a second embodiment of a resistive current measurement device 200. In this embodiment, the substrate 110 comprises an isolating layer 116 that carries the first and second conductive layers 112, 114. In this example, the plurality of resistors 120 comprises a single group of resistors 120 that is arranged on the first conductive layer 112 of the substrate 110. The resistors 120 are in close contact with the first conductive layer 112 at their first ends. A direct contact between the resistors and the conductive layer may be present, e. g. formed by press fit or welding, but also an intermediate material, such as solder or a conductive glue pad, or the like, may be present between the respective resistor 120 and the conductive layer 112.

[0064] To provide a low ohmic electrical contact between the second ends of the resistors 120 with the second conductive layer 114, a connection structure or connecting element may be used. The connection structure may be provided as one or a plurality of bond wires, bond ribbons, bond metal sheets, or the like. Also, a full metal contact may be provided by soldering or welding. Additionally, a conductive layer may be formed on the group of resistors 120, as is illustrated in Fig. 2.

[0065] In this example, the first and second conductive layers 112, 114 are arranged on a same side of the isolating layer 116. An air gap separates the conductive layers 112, 114 from each other. In other embodiments, isolating material may be provided in a space between the conductive layers 112, 114.

[0066] It is understood that the first conductive layer 112 and / or the second conductive layer 114 may be formed in some sections of the substrate 110, while other sections of the substrate 110 are not covered with one or both of the first conductive layer 112 and the second conductive layer 114. In other words, the substrate 110 may include sections formed by only the isolating layer 116, or formed by the isolating layer 116 and one of the first conductive layer 112 or the second conductive layer 114, or formed by either the first or second conductive layer 112, 114 alone, without the isolating layer being present. In embodiments, the substrate 110 may include further layers, for example additional isolating layers and / or additional conductive layers above the first conductive layer 112 and / or below the second conductive layer 114. In other words, the substrate 110 may have a multi-layer structure. In further embodiments, the first and / or second conductive layer 112, 114 may be structured and provide current paths with a certain shape, for example to tune a parasitic inductance of the respective current path and / or tune an inductive coupling of the respective current path with other conductive elements nearby. In further embodiments, the plurality of resistors 120 may be at least partially covered by additional isolating layers and / or additional conductive layers, for example for passivation and / or shielding purposes.

[0067] Fig. 3 illustrates a cross section of a third embodiment of a resistive current measurement device 300. The resistive current measurement device 300 comprises a substrate 110 comprising a first conductive layer 112, a second conductive layer 114, and an isolating layer 116 disposed between the first conductive layer 112 and the second conductive layer 114.

[0068] Resistive current measurement device 300 further includes a plurality of resistors 120. Here, each resistor 120 of the plurality of resistors 120 is arranged in the substrate 110 and connected to the first conductive layer 112 at a first end and connected to the second conductive layer 114 at a second end, such that all resistors 120 of the plurality of resistors 120 are connected in parallel between the first conductive layer 112 and the second conductive layer 114. Here, the substrate 110 extends in a horizontal direction and the resistors 120 extend in a vertical direction through the isolating layer 116 of the substrate 110. One may also say that the resistors 120 are integrated in or embedded in the substrate 110 or in the isolating layer 116. The resistors 120 forming the plurality or resistors 120 are arranged in a row. In this example, the resistors 120 are arranged next to each other with no material in between neighboring resistors 120. In embodiments, a gap may be provided between some or all of the resistors 120. The gap may partially or fully be filled with air and / or isolating material and / or with a material having a high thermal conductivity, such that heat generated in the resistors 120 can be dissipated quickly. In other embodiments not shown herein, the resistors 120 may be arranged in the substrate 110 at an angle other than orthogonal, for example at an angle of 45° with respect to the horizontal direction defined by the substrate 110. Other angles are also possible, for example between 10° - 90°.

[0069] In alternative implementations, only some resistors 120 of the plurality of resistors 120 are integrated in the substrate 110, while other resistors 120 of the plurality of resistors 120 may be arranged outside the substrate, such as shown in Fig. 1 or 2, for example.

[0070] The electrical connection between the respective conductive layer 112, 114 and the respective resistor 120 may be established by soldering, welding or press fitting, for example. Thus, a portion of the conductive layers 112, 114 may be formed from solder, such as in the area where the resistors 120 are arranged.

[0071] In the example shown in Fig. 3, the resistors 120 have a length (i.e., the distance between their ends) that corresponds to the thickness of the isolating layer 116. In other embodiments, the resistors 120 may extend through at least one of the conductive layers 112, 114, or may be shorter than shown here. In preferred embodiments, the resistors 120 have a length that is between a thickness of the isolating layer 116 and a thickness of the substrate 110.

[0072] The resistive current measurement device 300 further includes a first measurement terminal 132 connected to the first conductive layer 112 and a second measurement terminal 134 connected to the second conductive layer 114. The first and second measurement terminal 132, 134 are each configured for connecting a voltage measurement device VM for measuring a voltage across the plurality of resistors 120.

[0073] In embodiments, one of the first or second measurement terminal 132, 134 is arranged in close proximity to a reference potential connection terminal. The reference potential connection terminal may be provided additionally on the resistive current measurement device 300. Alternatively, one of the first or second measurement terminal 132, 134 is used to define a reference potential for the resistive current measurement device 300. In this regard, the reference potential serves as the reference electrical potential that is used to refer all other electrical potentials to when measuring a voltage using the resistive current measurement device. For example, an oscilloscope used to record a time resolved voltage reading may be referred to the same reference potential. This has the advantage that the voltage across the resistive current measurement device 300 may be measured with high fidelity and with no or only negligible impact, such as an offset due to induced voltages or currents.

[0074] In an embodiment of the resistive current measurement device 300, the substrate 110 has a planar shape extending in a first and a second horizontal direction, and a current II flowing between the first conductive layer 112 and the second conductive layer 114 via the plurality of resistors 120 flows through the respective resistor 120 with a vertical vector component.

[0075] Fig. 4 illustrates a top view of a fourth embodiment of a resistive current measurement device 400. In this embodiment, the resistors 120 forming the plurality or resistors 120 are arranged in an array arrangement having rows extending in a first direction and columns extending in a second direction. The first and second direction extend in the horizontal plane defined by the substrate 110 in this example. However, such array arrangement of the resistors 120 may also be arranged vertically, i.e. one of the first or second direction extending in a vertical direction with respect to the substrate 110. In this example, the first and second direction are orthogonal to each other, but other relative arrangements are also possible. One may also say that the resistors 120 form a matrix of resistors, where each cell of the matrix denotes the position of a resistor 120. In embodiments, some cells of the matrix may be left empty, i.e. without a resistor 120.

[0076] For example, the resistors 120 are integrated into the substrate 110, as is explained referring to Fig. 3 above. Thus, the conductive layers 112, 114 are arranged on opposite surfaces of the substrate 110. Indicated by a dashed line is the area of the substrate 110 covered with first conductive layer 112. In this example, the first conductive layer 112 does not cover the whole surface of the substrate 110, but only a section including the array of resistors 120. Additionally, the first measurement terminal 132 is in contact with the first conductive layer 112, as is indicated by the first conductive layer extending around the first measurement terminal 132. The second measurement terminal 134 is also provided on the top side of the substrate 110 in this example, to allow for a simple connection of the voltage measurement device VM from one side of the substrate 110. For example, the second measurement terminal 134 may be connected to the second conductive layer 114, which is arranged on the other side of the substrate 110 and not visible in this view, by a via extending through the isolating layer 116. In other words, the first and second measurement terminal 132, 134 may both be arranged on a same side of the substrate 110.

[0077] It is noted that the array arrangement of the plurality of transistors 120 may also be used in additional embodiments based on the first embodiment described referring to Fig. 1 or the second embodiment described referring to Fig. 2.

[0078] Fig. 5 illustrates a top view of a fifth embodiment of a resistive current measurement device 500, which is also based on the embodiment described referring to Fig. 3. In this embodiment, the plurality of resistors 120 comprises at least a first group 120A of resistors 120 and a second group 120B of resistors 120, each of the first and second group 120A, 120B comprising at least two resistors 120. The first group 120A of resistors 120 is arranged in a first section of the substrate 110 and the second group 120B of resistors 120 is arranged in a second section of the substrate 110. The first section and the second section are separated by a separation region 118 of the substrate 110. A width of the separation region 118 may be selected such that the first and second measurement terminals 132, 134 may be arranged in the separation region 118, for example. The separation region 118 may be formed, at least in part, by a section of the isolating layer 116 of the substrate 110. The separation region 118 may be free of the first conductive layer 112 and / or of the second conductive layer 114. In this example, the first conductive layer 112, indicated by a dashed line, covers both groups 120A, 120B of resistors 120 and a section of the substrate 110, but does not cover the area of the separation region 118 between the groups 120A, 120B. Therefore, when a voltage is applied between the first and second conductive layers 112, 114, there is no load current flowing in the separation region 118.

[0079] In this embodiment, the first measurement terminal 132 and the second measurement terminal 134 are provided in the form of coaxial terminals arranged in the separation region 118. Second measurement terminal 134 may be connected to the second conductive layer 114 through a via in the isolating layer 116. Since no load current is flowing in the separation region 118, a voltage measurement signal that is provided via the measurement terminals 132, 134 is essentially undisturbed by load currents, which allows to measure the voltage with higher sensitivity and less error.

[0080] In this embodiment, the relative arrangement of the groups 120A, 120B is symmetric and the measurement terminals 132, 134 are centered relative to the groups 120A, 120B, such that a current flow though the plurality of resistors 120 is also symmetric with respect to the measurement terminals 132, 134, which minimizes adverse effects that could compromise the measurement. However, this arrangement is only an example, and other arrangements, where the groups 120A, 120B and / or the measurement terminals 132, 134 are not arranged in such symmetric way, are also possible.

[0081] It is noted that providing groups of resistors with a separation region between groups and providing the measurement terminals in the separation region may also be used in additional embodiments based on the first embodiment described referring to Fig. 1 or the second embodiment described referring to Fig. 2.

[0082] Fig. 6 illustrates a cross section of the fifth embodiment of a resistive current measurement device 500. In this embodiment, the plurality of resistors 120 is provided in two groups 120A, 120B, that are separated by a separation region 118. The separation region 118 is formed by a part of the isolating layer 116 of the substrate 110, except for a conductive via that connects the second measurement terminal 134 with the second conductive layer 114. Additionally, the first and second measurement terminal 132, 134 are provided as terminals of a voltage probe connector 130, which is provided as a coaxial plug or coaxial socket in this embodiment. Voltage probe connector 130 may be attached to the substrate 110 in the separation region 118, for example. Other kinds of voltage probe connectors are also possible, such as micro-miniature coaxial (MMCX) connectors, oscilloscope probe adapters with various diameters, such as 2.5mm, 3.5mm, 5mm, 8mm or others, and / or simple pin headers. Voltage probe connector 130 allows to quickly and securely connect / disconnect a voltage measurement device VM with the resistive current measurement device 500. Fig. 7 illustrates a cross section of a sixth embodiment of a resistive current measurement device 600. In this embodiment, the first conductive layer 112 and the second conductive layer 114 each extend only in one direction from the plurality of resistors 120, such that a load current essentially flows in one direction (from right to left in Fig. 7). Additionally, the conductive layers 112, 114 are respectively covered by an isolating layer 116. This provides for isolation of the conductive layers 112, 114 and thus increases safety when handling the resistive current measurement device 600.

[0083] In Fig. 7, a load current flow II is illustrated by arrows. In this example, the current flows in a horizontal direction in the first conductive layer 112, then in a vertical direction through the plurality of resistors 120, and the again in a horizontal direction in the second conductive layer 114. Of course, a current flow in the opposite direction is also possible. This illustration shows that the resistive current measurement device 100, 200, 300, 400, 500, 600 according to embodiments disclosed herein can be made with a very low parasitic inductance, and thus support a high bandwidth for measurement of high frequency currents or steep di / dt switching events without distorting the measurement.

[0084] In embodiments, the resistors 120 may be respectively comprised in a respective package. The package may protect the resistive element from external influences, and may isolate the resistive element to the outside. The package may comprise a first contact pad and a second contact pad. For example, some or all resistors 120 may be provided as a surface-mount device (SMD).

[0085] In embodiments, each resistor 120 has a power rating of at least 100 mW, preferably 500 mW, more preferred 1 W. The power rating of a resistor corresponds to the power which the resistor can dissipate without risk of destroying the resistor.

[0086] In embodiments, the plurality of resistors 120 includes at least 20 resistors, preferably at least 30 resistors, more preferred at least 40 resistors. The larger the number of resistors, the lower the parasitic inductance and the higher the total power rating of the resistive current measurement device 100, 200, 300, 400, 500, 600. Therefore, by tuning the number of resistors 120 used as well as their individual resistance values, an optimal configuration for a given application scenario can be found, wherein the application scenario defines the required bandwidth and total power rating of the resistive current measurement device 100, 200, 300, 400, 500, 600.

[0087] In embodiments, a total inductance of the resistive current measurement device is equal to or less than 100 pH, preferably equal or less than 50 pH, more preferred equal or less than 20 pH.

[0088] Fig. 8 illustrates a diagram 700 showing a frequency response Rf of a resistive current measurement device 100, 200, 300, 400, 500, 600, for example the device described referring to one of Fig. 1 to 7. The horizontal axis of the diagram shows a frequency f, for example in Hertz (Hz), and the vertical axis of the diagram shows a signal strength S, for example in decibel (dB). The frequency response Rf is proportional to the impedance of the device. At low frequency, such as below 1 kHz for example, the frequency response Rf has a value denoted as baseline BL. The baseline value corresponds to the pure ohmic contribution of the resistive current measurement device. The frequency response Rf is essentially constant over a certain frequency range, which means that the impedance of the device is constant for current signals with a spectrum within that frequency range. However, at a threshold frequency BW the frequency response Rf starts to increase significantly in this example. This behavior may be caused by the fast current change for such high frequency current signals, which may induce a voltage over the inductance of the device that is sampled by the voltage measurement device, leading to an increase of the signal. The threshold frequency BW may be referred to as the bandwidth of the device and corresponds to the frequency at which the frequency response Rf deviates by 3 dB from the baseline value BL. In other words, the impedance of the device changes significantly above the threshold frequency BW. Thus, current signals with frequency higher than the threshold frequency BW will be transmitted through the device different than those having a frequency below the threshold frequency BW, which may result in a distorted current measurement for such signals. In embodiments, the resistive current measurement device 100, 200, 300, 400, 500, 600 has a bandwidth BW of at least 500 MHz, preferably at least 1 GHz, and more preferred at least 2 GHz.

[0089] Fig. 9 illustrates a schematic circuit diagram of a current measurement arrangement 800 according to one or more implementations. The current measurement arrangement 800 comprises a resistive current measurement device 100, which may be implemented as described referring to any one Fig. 1 - 7, for example. The current measurement arrangement 800 further includes a voltage measurement device VM that is connected to the first measurement terminal 132 and the second measurement terminal 134. For measuring a current flowing in a load current path of another circuit, the current measurement arrangement 800 can be inserted into the load current path at the terminals T 1 and T2, such that the load current flows through the resistive current measurement device 100, generating a voltage across the device that is proportional to the load current. The voltage measurement device VM is then used to measure the voltage to get a measure of the load current. Having a high bandwidth, low parasitic inductance and low ohmic resistance, the resistive current measurement device does essentially not influence the load current and the load current may be monitored with a high time resolution, and even oscillations of the load current in the hundreds of MHz or even GHz range can be measured correctly.

[0090] Fig. 10 illustrates a schematic circuit diagram of a test setup 900 for measuring a transient current response of a transistor under test DUT according to one or more implementations. The test setup 900 includes a power source PS configured to provide a predefined current at a predefined voltage. The power source PS may be provided by one or a plurality of capacitors, which may be charged to the predefined voltage, and / or it may comprise an inductive element that may be charged to drive a specific current and voltage. The test setup 900 includes a first load terminal TL1 connected to a first terminal of the power source PS and configured to be connected to a first transistor load terminal of the transistor under test DUT, a second load terminal TL2 connected to a second terminal of the power source PS and configured to be connected to a second transistor load terminal of the transistor under test DUT, and a gate terminal TG configured to be connected to a transistor gate terminal of the transistor under test DUT. In this example, the transistor under test DUT is a MOSFET, for example a silicon carbide MOSFET, that is connected to the respective terminals TL1 , TL2, TG and ready for testing. The test setup 900 may further include a gate driver GD connected to the gate terminal TG and configured for sourcing and sinking a gate current to drive the transistor under test DUT between switching states. The gate driver GD is selected based on the transistor under test DUT and the required current sourcing / sinking capabilities. In this example, the gate driver GD is referenced to the source terminal of the transistor under test DUT. In embodiments, a control signal SIG may be provided to the gate driver GD from an external controller. Additionally, the test setup 900 includes a current measurement arrangement 800 as described referring to Fig. 9. The current measurement arrangement 800 is connected between the second terminal of the power source PS (e.g., an anode or a cathode of the power source PS) and the second load terminal TL2 in this example.

[0091] Therefore, a load current flowing through the transistor under test DUT also flows through the resistive current measurement device 100, causing a voltage that is proportional to the current and that can be measured by the voltage measurement device VM. It is noted that other circuit elements, such as resistors or reactors, may also be present in the test setup 900, but are omitted in this schematic.

[0092] In embodiments, the test setup 900 may be extended to a double-pulse setup, for example, or a specific circuit that more closely resembles an actual application circuit in order to test the transistor under test DUT under conditions similar to those that are expected in a given specific application. Particularly, the transistor under test DUT may be connected in a halfbridge arrangement with another transistor, in particular a same transistor, on the high side or low side, and a reactor in parallel to the other transistor, that may act as current source for testing the transistor under test DUT. Instead of another transistor, a diode may be used, for example. Such kind of setup is sometimes referred to as “double-pulse” setup, although the number of pulses is not restricted.

[0093] The test setup 900 may be used to determine turn-on and turn-off transients of the transistor under test DUT at a predefined DC bus voltage and a predefined load current. Fig. 11A shows schematic current, voltage and power diagrams of a turn-on transient measured using a test setup 900 as shown in Fig. 10, and Fig. 11B shows corresponding current, voltage and power diagrams of a turn-off transient. The transistor under test DUT was a silicon carbide MOSFET in this example. In Fig. 11A and Fig. 11 B, the top diagram shows the drain-source current Ids in Ampere [A] (this is also referred to as load current herein), the middle diagram shows the drain-source voltage Vds in Volt [V] and the lower diagram shows a power dissipation Pds in kilowatts [kW] occurring in the transistor, which corresponds to the switching losses. The horizontal axis shows the time t in nanoseconds [ns].

[0094] For example, the resistive current measurement device 100, 200, 300, 400, 500, 600 used for recording these traces includes 40 thick film resistors, each having a nominal resistance value of 3 Ohm, resulting in a total resistance of 75 mOhm and a total inductance of about 11 pH. The bandwidth of this device 100, 200, 300, 400, 500, 600 is therefore around 1 .2 GHz. The power source PS was configured to provide a DC bus voltage of about 800 V and a steady-state current of about 500 A. The resistive current measurement device 100, 200, 300, 400, 500, 600 is used to measure the load current Ids. For example, an oscilloscope may be used as the voltage measurement device VM to record a time-resolved trace of the load current Ids.

[0095] For the turn-on transient (Fig. 11 A) a di / dt value of more than 12.6 A / ns is achieved. The total duration of the turn-on is on the order of 80 ns in this example. As can be seen, the fast turnon leads to oscillations in the load current Ids and drain-source voltage Vds, including an overshooting of the load current to over 600 A. The oscillations have a frequency of around 50 MHz in this example. A total energy dissipated in the MOSFET Eon is on the order of 8 mJ for the single turn-on event.

[0096] For the turn-off transient (Fig. 11 B) a di / dt value of more than 12.6 A / ns is achieved. The total duration of the turn-off is on the order of 70 ns in this example. An overshooting drain-source voltage Vds to about 1200 V can be seen. As for the turn-on, oscillations are present with a frequency of about 50 MHz. A total energy dissipated in the MOSFET Eoff is on the order of 15 mJ for the single turn-off event.

[0097] In embodiments, the resistive current measurement device 100, 200, 300, 400, 500, 600 is configured for conducting a current of at least 200 A, preferably at least 400 A, more preferred at least 600 A, in a pulse having a duration between 1 ps up to 1000 ps, preferably between 10 ps to 500 ps.

[0098] In embodiments, the resistive current measurement device 100, 200, 300, 400, 500, 600 has a maximum pulse energy rating of 100 J (Joules), or a maximum pulse energy rating of 30 J, or a maximum pulse energy rating of 10 J, or a maximum pulse energy rating of 3 J.

[0099] The pulse energy rating is a measure of a maximum energy that the resistive current measurement device can absorb during an energy pulse without failing. The pulse energy rating relates to the energy absorbed in a single pulse. Here, a duration of a pulse may be up to 1 ms, for example. For example, when measuring a turn-on and / or turn-off transient of a power transistor using the resistive measurement device, the pulse duration is given by the on time of the transistor, when the load current is conducted through the resistive current measurement device. The pulse energy may be calculated based on the duration of the pulse, the current magnitude and the resistance value of the resistive measurement device 100, 200, 300, 400, 500, 600.

[0100] Fig. 12 illustrates an embodiment of a method for measuring a current in a connection between a first circuit node and a second circuit node of an electrical circuit. For example, the electrical circuit may be the test setup 900 of Fig. 10, and the circuit nodes may be the second load terminal TL2 and the anode of the power source PS. In a first step S1 , the method comprises connecting a resistive current measurement device 100, 200, 300, 400, 500, 600, for example one of the devices described referring to Fig. 1 to 7, between the first circuit node and the second circuit node. In a second step S2, a voltage measurement device VM is connected to the first measurement terminal T 1 and to the second measurement terminal T2 of the device. In a third step S3, the current to be measured is driven through the resistive current measurement device. In a fourth step S4, a voltage across the resistive current measurement device is determined using the voltage measurement device VM. Based on the measured voltage the current may be obtained.

[0101] The method may be used for measuring a load current of a transistor, for example. In particular, the method may be used for measuring a load current transient when the transistor is turned on or turned off. The method may therefore further comprise the steps of connecting a transistor in series with the resistive current measurement device, such that a load current through the load path of the transistor must flow through the resistive current measurement device. A further step may include connecting a gate driver to a gate of the transistor for controlling the switching state of the transistor. A further step may include driving the transistor between an off-state and an on-state using the gate driver to control the gate voltage.

[0102] Fig. 13 illustrates an embodiment of a method for manufacturing a resistive current measurement device, for example one of the devices described referring to Fig. 1 to 7. In a first step S10, the method comprises providing a substrate 110 comprising a first conductive layer 112 and a second conductive layer 114. In a second step S11 , a plurality of resistors 120 is arranged at the substrate 110. In a third step S12 a first terminal of each resistor 120 of the plurality is electrically connected with the first conductive layer 112. This may involve soldering, welding, glueing, clamping, press fitting or another method suitable for electrically connecting the resistor with the conductive layer. The connection preferably also provides mechanical support, i.e. attaches the resistor 120 to the conductive layer. In a fourth step S13 a second terminal of each resistor 120 of the plurality is electrically connected with the second conductive layer 114. In a fifth step S14 a first measurement terminal 132 connected to the first conductive layer 112 is provided and a second measurement terminal 134 connected to the second conductive layer 114 is provided. The first and second measurement terminals 132, 134 are configured for connecting a voltage measurement device VM for measuring a voltage across the plurality of resistors 120.

[0103] In embodiments, the method may comprise removing at least one section from the substrate 110 to provide an insertion area in the substrate 110. The removing may include one or more of sawing, drilling, milling, etching, punching, embossing, hot-embossing, or any other suitable method for material removal. In addition, the substrate 110 may also be provided having the insertion area, for example by manufacturing the substrate from a liquid in a casting or molding process and using a suitable injection mold. The method may further include arranging the plurality of resistors 120 in the insertion area. Here, the first and second conductive layers 112, 114 may also be provided by galvanic deposition. In embodiments, the electrical connection between the individual resistors 120 and the conductive layers 112, 114 may be provided using bonding wires and / or bonding ribbons or other electrical connection elements that can be fixed to both the conductive layers and the respective terminal of the resistors 120.

[0104] It is noted that the above-described methods are only exemplary and do not exclude that further steps are performed, either before, after or in between the recited method steps. In addition, the order of the method steps as presented herein must not be construed as limiting, and the order of steps may be changed without departing from the scope of this disclosure.

[0105] The present disclosure may further be illustrated by the following examples.

[0106] In some examples a resistive current measurement device comprises: a substrate comprising a first conductive layer and a second conductive layer that is separate from the first conductive layer; a plurality of resistors arranged at the substrate, wherein each resistor of the plurality is connected between the first conductive layer and the second conductive layer; and a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminals are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

[0107] In some examples of the resistive current measurement device the plurality of resistors comprises at least one group of resistors, each group of resistors comprising at least two resistors that are packed in close contact to each other.

[0108] In some examples of the resistive current measurement device the at least one group of resistors is arranged on the first conductive layer or on the second conductive layer.

[0109] In some examples of the resistive current measurement device the substrate extends in a horizontal plane, and the resistors of the plurality of resistors are stacked on each other forming a stack of resistors, wherein the stack of resistors extends in a vertical direction from the substrate.

[0110] In some examples of the resistive current measurement device the substrate extends in a horizontal plane and the plurality of resistors comprises at least two stacks of resistors, each stack comprising at least two resistors stacked on each other, each stack extending in a vertical direction from the substrate and wherein the two stacks are arranged at different positions at the substrate.

[0111] In some examples of the resistive current measurement device the substrate comprises an isolating layer that carries the first conductive layer and the second conductive layer.

[0112] In some examples of the resistive current measurement device the first and second conductive layers are arranged on opposite sides of the isolating layer, and the plurality of resistors is arranged in the substrate, such that a current path is provided through the isolating layer from the first conductive layer to second conductive layer.

[0113] In some examples of the resistive current measurement device the plurality of resistors comprises at least a first group of resistors and a second group of resistors, each of the first and second group comprising at least two resistors; the first group of resistors is arranged in a first section of the substrate; the second group of resistors is arranged in a second section of the substrate; and the first section and the second section are separated by a separation region of the substrate.

[0114] In some examples of the resistive current measurement device the separation region is formed by an isolating material.

[0115] In some examples of the resistive current measurement device the first measurement terminal and the second measurement terminal are arranged in the separation region.

[0116] In some examples of the resistive current measurement device a voltage probe connector is attached to the substrate and connected to the first measurement terminal and the second measurement terminal.

[0117] In some examples of the resistive current measurement device each resistor is comprised in a package, the package having the first contact pad and the second contact pad.

[0118] In some examples of the resistive current measurement device the substrate is a printed circuit board.

[0119] In some examples of the resistive current measurement device the plurality of resistors may include resistors of a thin film type, a thick film type, a metal strip type and / or a full volume conductivity type.

[0120] In some examples of the resistive current measurement device each resistor has a power rating of at least 100 mW, preferably 500 mW, more preferred 1 W.

[0121] In some examples of the resistive current measurement device a bandwidth of the resistive current measurement device is at least 500 MHz, preferably at least 1 GHz, and more preferred at least 2 GHz.

[0122] In some examples of the resistive current measurement device the resistive current measurement device is configured for conducting a current of at least 200 A, preferably at least 400A, more preferred at least 600 A, in a pulse having a duration between 1 ps up to 100 ps, preferably 10 ps to 50 ps.

[0123] In some examples of the resistive current measurement device the resistive current measurement device has a maximum pulse energy rating of 100 J, or a maximum pulse energy rating of 30 J, or a maximum pulse energy rating of 10 J, or a maximum pulse energy rating of 3 J.

[0124] In some examples of the resistive current measurement the plurality of resistors includes at least 20 resistors, preferably at least 30 resistors, more preferred at least 40 resistors. In some examples of the resistive current measurement a total inductance of the resistive current measurement device is equal to or less than 100 pH, preferably equal or less than 50 pH, more preferred equal or less than 20 pH.

[0125] In some examples a method for manufacturing a resistive current measurement device comprises:

[0126] Providing a substrate comprising a first conductive layer and a second conductive layer;

[0127] Arranging a plurality of resistors at the substrate,

[0128] Electrically connecting a first terminal of each resistor of the plurality with the first conductive layer,

[0129] Electrically connecting a second terminal of each resistor of the plurality with the second conductive layer; and

[0130] Providing a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminal are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

[0131] In some examples a method for measuring a current in a connection between a first circuit node and a second circuit node of an electrical circuit comprises:

[0132] Connecting a resistive current measurement device according to any one of examples one to eighteen between the first circuit node and the second circuit node;

[0133] Connecting a voltage measurement device to the first measurement terminal and the second measurement terminal;

[0134] Driving the current to be measured through the resistive current measurement device; and Determining a voltage across the resistive current measurement device with the voltage measurement device.

[0135] In some examples a current measurement arrangement comprises a resistive current measurement device according to any one of examples one to eighteen, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal. In some examples a transistor test setup configured for measuring a transient current response of a transistor under test comprises a power source, a first load terminal connected to a first terminal of the power source and configured to be connected to a first transistor load terminal of the transistor under test, a second load terminal connected to a second terminal of the power source and configured to be connected to a second transistor load terminal of the transistor under test, a gate terminal configured to be connected to a transistor gate terminal of the transistor under test, a resistive current measurement device according to one of examples one to eighteen and connected in series between the power source and the first load terminal or the second load terminal, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal.

[0136] Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific examples discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.

[0137] It should be noted that the methods and devices including its preferred embodiments as outlined in the present document may be used stand-alone or in combination with the other methods and devices disclosed in this document. In addition, the features outlined in the context of a device are also applicable to a corresponding method, and vice versa.

[0138] Furthermore, all aspects of the methods and devices outlined in the present document may be arbitrarily combined. In particular, the features of the claims may be combined with one another in an arbitrary manner.

[0139] It should be noted that the description and drawings merely illustrate the principles of the proposed methods and systems. Those skilled in the art will be able to implement various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples and embodiments outlined in the present document are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the proposed methods and systems. Furthermore, all statements herein providing principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.

Claims

CLAIMS1. A resistive current measurement device, comprising: a substrate comprising a first conductive layer and a second conductive layer that is separate from the first conductive layer; a plurality of resistors arranged at the substrate, wherein each resistor of the plurality of resistors is connected between the first conductive layer and the second conductive layer; and a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminals are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

2. The resistive current measurement device of claim 1 , wherein the plurality of resistors comprises at least one group of resistors, each group of resistors comprising at least two resistors that are arranged in close contact to each other.

3. The resistive current measurement device of claim 2, wherein the at least one group of resistors is arranged on at least one of the first conductive layer and the second conductive layer.

4. The resistive current measurement device of any one of the preceding claims, wherein the substrate extends in a horizontal plane, and the resistors of the plurality of resistors are stacked on each other forming a stack of resistors, wherein the stack of resistors extends in a vertical direction from the substrate.

5. The resistive current measurement device of any one of the preceding claims, wherein the substrate comprises an isolating layer.

6. The resistive current measurement device of claim 5, wherein the first and second conductive layers are arranged on opposite sides of the isolating layer.

7. The resistive current measurement device of any one of the preceding claims, wherein at least some resistors of the plurality of resistors are arranged in the substrate.

8. The resistive current measurement device of any of the preceding claims, wherein the plurality of resistors comprises at least a first group of resistors and a second group of resistors, each of the first and second group comprising at least two resistors; the first group of resistors is arranged in a first section of the substrate; the second group of resistors is arranged in a second section of the substrate; and the first section and the second section are separated by a separation region of the substrate.

9. The resistive current measurement device of claim 8, wherein: the separation region is formed by an isolating material.

10. The resistive current measurement device of claim 9, wherein: the first measurement terminal and the second measurement terminal are arranged in the separation region.11 . The resistive current measurement device of any of the preceding claims, wherein: the plurality of resistors includes resistors of a thin film type, a thick film type, a metal strip type and / or a full volume conductivity type.

12. The resistive current measurement device of any of the preceding claims, wherein each resistor has a power rating of at least 100 mW, preferably 500 mW, more preferred 1 W.

13. The resistive current measurement device of any of the preceding claims, wherein: a bandwidth of the resistive current measurement device is at least 500 MHz, preferably at least 1 GHz, and more preferred at least 2 GHz.

14. The resistive current measurement device of any of the preceding claims, wherein: the resistive current measurement device is configured for conducting a current of at least 200 A, preferably at least 400 A, more preferred at least 600 A, in a pulse having a duration between 1 ps up to 1000 ps, preferably 10 ps to 500 ps.

15. The resistive current measurement device of any of the preceding claims, wherein the resistive current measurement device has a maximum pulse energy rating of 100 J, or a maximum pulse energy rating of 30 J, or a maximum pulse energy rating of 10 J, or a maximum pulse energy rating of 3 J.

16. The resistive current measurement device of any of the preceding claims, wherein: the plurality of resistors includes at least 20 resistors, preferably at least 30 resistors, more preferred at least 40 resistors.

17. The resistive current measurement device of any of the preceding claims, wherein: a total inductance of the resistive current measurement device is equal to or less than 100 pH, preferably equal or less than 50 pH, more preferred equal or less than 20 pH.

18. A method for manufacturing a resistive current measurement device, the method comprising:Providing a substrate comprising a first conductive layer and a second conductive layer;Arranging a plurality of resistors at the substrate, ,Electrically connecting a first terminal of each resistor of the plurality with the first conductive layer,Electrically connecting a second terminal of each resistor of the plurality with the second conductive layer; andProviding a first measurement terminal connected to the first conductive layer and a second measurement terminal connected to the second conductive layer, wherein the first and second measurement terminal are configured for connecting a voltage measurement device for measuring a voltage across the plurality of resistors.

19. A method for measuring a current in a connection between a first circuit node and a second circuit node of an electrical circuit, the method comprising:Connecting a resistive current measurement device according to any one of claims 1 to 17 between the first circuit node and the second circuit node;Connecting a voltage measurement device to the first measurement terminal and the second measurement terminal;Driving the current to be measured through the resistive current measurement device; andDetermining a voltage across the resistive current measurement device with the voltage measurement device.

20. A current measurement arrangement, comprising: a resistive current measurement device according to any one of claims 1 to 17, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal.21 . A transistor test setup configured for measuring a transient current response of a transistor under test, comprising: a resistive current measurement device according to one of claims 1 to 17, a power source, a first load terminal connected to a first terminal of the power source and configured to be connected to a first transistor load terminal of the transistor under test, a second load terminal connected to a second terminal of the power source and configured to be connected to a second transistor load terminal of the transistor under test, a gate terminal configured to be connected to a transistor gate terminal of the transistor under test, and a voltage measurement device connected to the first measurement terminal and the second measurement terminal, wherein the resistive current measurement device is connected in series between the power source and the first load terminal or the second load terminal.

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