Current sensor assembly, PCB with current sensors, power invertor

Abstract

A current sensor assembly (1600; 1700; 1800; 1900; 2200; 2400; 2800; 2900) comprising a plurality of electrical conductors (20), each having two main body portions (21, 22) and two parallel interconnection portions (23, 24) with an opening (25) between them; a printed circuit board (10) comprising a plurality of cut-outs (44) and lips (11), each lip accommodating a sensor device (30) with at least four electrical contacts to the PCB (10), each sensor device (30) comprising a semiconductor substrate (31) parallel to the PCB, and comprising a plurality of magnetic sensors for measuring in-plane magnetic field components (Bx, By); each semiconductor substrate (10) arranged partially inside the openings (25) and oriented perpendicular to the interconnection portions. A printed circuit board (10) having a plurality of cut-outs (44) and lips (11) and magnetic sensor devices (30). A power invertor comprising such current sensor assembly and / or such a PCB.

Description

[0001] CURRENT SENSOR ASSEMBLY, PCB WITH CURRENT SENSORS, POWER INVERTOR

[0002] Field of the invention

[0003] The present invention relates to the field of current sensor devices and systems, and in particular to current sensor assemblies comprising a plurality of at least two conductors having an opening, and a single printed circuit board having lips (or protrusions) and current sensors mounted on said lips, the lips being inserted in said openings.

[0004] Background of the invention

[0005] Current sensor devices and systems are known in the art. They are used for example to measure and to control the flow of currents in electrical motors, e.g. of electrical vehicles, or in DC-to-AC power convertors (also known as invertors), and the like.

[0006] In contrast to for example the power generated by a solar power installation and delivered to the power grid at a constant frequency of about 50 Hz or 60 Hz, the currents that need to be delivered to the coils of an electrical motor of an electrical vehicle typically contain much higher frequencies, e.g. up to 1000 Hz, or up to 1500 Hz, or up to 2000 Hz.

[0007] There are many challenges for power delivery systems in electrical vehicles, for example related to weight and compactness, accuracy, long term stability, long term mechanical stability, robustness against positioning errors, robustness against external disturbances, complexity, cost, reliability, safety, mounting tolerances, ease of assembly, etc.

[0008] US2021311136(Al) discloses a current sensor system comprising a plurality of conductors, each having an aperture, and the apertures of the conductors are aligned with a common reference line, such that a long and narrow printed circuit board (PCB) with multiple sensor devices can be inserted through the different apertures for measurement of the different currents.

[0009] There is always room for improvements or alternatives.

[0010] Summary of the invention

[0011] It is an object of the present invention to provide a current sensor assembly comprising a plurality of at least two conductors each having an opening, and a printed circuit board with a plurality of sensor devices, each positioned at least partially in a corresponding opening.

[0012] It is an object of embodiments of the present invention to provide such a current sensor assembly where the currents are measured with good accuracy, e.g. in terms of SNR, and / or are highly robust against an external disturbance field, and / or are highly robust against mechanical positioning errors (in particular with respect to the sensor device relative to the openings of the conductors).

[0013] It is an object of embodiments of the present invention to provide such a current sensor assembly where the currents are measured with an absolute error smaller than ± 5% for frequencies up to 1500 Hz, and / or smaller than ± 4% for frequencies up to 1000 Hz, even without a magnetic shielding, and even without using cross-talk compensation calculations.

[0014] It is an object of embodiments of the present invention where the currents are measured which is less sensitive to mechanical positioning errors of the sensor devices relative to the conductors.

[0015] It is also an object of the present invention to provide a printed circuit board with a plurality of sensor devices for use in such a current sensor assembly.

[0016] These and other objectives are accomplished by embodiments of the present invention.

[0017] According to a first aspect, the present invention provides a current sensor assembly comprising: a plurality of at least two (or at least three) electrical conductors (e.g. busbars) for conducting at least two or at least three currents, each electrical conductor (e.g. busbar) having two main body portions and two interconnection portions disposed between the two main body portions and extending in parallel with an opening between them; a printed circuit board extending in a first direction (X) and in a second direction (Y) perpendicular to the first direction, and comprising at least two cut-outs and at least two lips or protrusions accommodating at least two sensor devices, each sensor device having at least four electrical contacts (e.g. pins or elongated leads) connected to the printed circuit board; each sensor device being or comprising a semiconductor substrate oriented parallel to the printed circuit board, and being arranged at least partially inside the opening of a corresponding electrical conductor (e.g. between the two interconnection portions); each sensor device comprising a plurality of magnetic sensors for measuring at least two magnetic field components oriented parallel to the semiconductor substrate; wherein the two interconnection portions of the electrical conductors extend in a third direction (Z) substantially perpendicular to the first and second direction (X, Y).

[0018] Examples of such a current sensor assembly are illustrated in FIG. 16A to FIG. 19B and in FIG. 22B, and in FIG. 24, and in FIG. 28 and in FIG. 29.

[0019] In an embodiment, the electrical conductors have an upright portion (e.g. oriented vertically), and a through-opening is made in this upright portion, such that the current flowing through the conductor has to locally flow through two upright pillars, also referred to as "interconnection portions" (e.g. as illustrated in FIG. ID).

[0020] In an embodiment, the electrical conductors have at least a vertical portion and directly connected thereto a horizontal portion, and the conductors comprise a through-opening that extends partially in the vertical portion and partially in the horizontal portion (e.g. as illustrated in FIG. 24 or FIG. 25 or FIG. 28 or FIG. 29). One could also say that the horizontal conductor portion has a horizontal slot, and the vertical conductor portion have a vertical slot, and these slots fit together. This embodiment offers as an important advantage that the lips of the PCB can be moved inside the openings from the top, and that the PCB can be moved into position by a mere vertical movement. The two interconnection portions may have an overall L-shape, and may comprise a long leg portion (e.g. oriented vertically) and a short leg portion (e.g. oriented horizontally), spaced apart from each other (e.g. as illustrated in FIG. 25).

[0021] In an embodiment, the electrical conductors may comprise two horizontal portions, and a vertical portion, and the two horizontal portions may be laterally offset from each other, and the vertical portion may be situated between the two horizontal portions, and welded thereto (e.g. as illustrated in FIG. 28).

[0022] An advantage of mounting the semiconductor substrate and / or the packaged device parallel to the PCB is that so called "di / dt interference" can be reduced. This is particularly advantageous when measuring a strong and a fast varying magnetic field.

[0023] With substantially perpendicular is meant "perpendicular within a tolerance margin of ±5° or ±3° or ±2° or ±1°.

[0024] The printed circuit board (PCB) is oriented perpendicular to the direction in which the interconnection portions of the busbar extend (i.e. the Z-direction), or perpendicular to the direction in which the current flows through the interconnection portions (i.e. the Z-direction), or parallel to a crosssection of the interconnection portions of the electrical conductor (as illustrated in FIG. ID and FIG. IE).

[0025] In certain embodiments, this PCB is not only intended for mounting the sensor devices relative to the busbars, but is also a main PCB of a power invertor, comprising also other electronic components or circuits or connectors, such as e.g. one or more of the following: a controller chip, filters (e.g. Low- Pass or Band-Pass filter), rectifiers, power switches, power transistors, diodes, power diodes, voltage regulators, half-bridge circuit, full-bridge circuit, a fuse, etc.

[0026] The at least two sensor devices (e.g. semiconductor substrates or packaged semiconductor devices, also known as "semiconductor chips") are mounted on a single PCB. The size of this PCB can vary widely, e.g. can be made very compact (see e.g. FIG. 21D or FIG. 21H or FIG. 33), or can be made relatively large (see e.g. FIG. 21A or FIG. 21B or FIG. 21E or FIG. 21F or FIG. 24 or FIG. 30).

[0027] The sensor devices are preferably "surface-mounted" on the PCB (in contrast to a package having e.g. three (relatively long) elongated pins oriented perpendicular to the PCB). The package may have a heat-dissipating contact surface in direct contact with an area of the PCB.

[0028] In an embodiment, the sensor device comprises a single semiconductor substrate.

[0029] In an embodiment, the sensor device comprises at least two semiconductor substrates, for example one main semiconductor substrate and only one satellite substrate, or one main substrate and two or four satellite substrates, electrically connected to the main semiconductor substrate, e.g. using at least one redistribution (RDL) layer, e.g. as used in "wafer level packaging" (WLP) processes, e.g. in manners similar as described in EP4328607(Al), incorporated herein by reference in its entirety, especially as illustrated in FIG. 1(a), FIG. 1(b), FIG. 4(g), FIG. 4(j), FIG. 5, and FIG. 7 thereof, but preferably having one or more vertical Hall elements or having one or more magneto-resistive elements, e.g. XMR elements. The "satellite substrates" may be CMOS substrates or GaAs substrates. The main substrate may be a CMOS substrate and may comprise at least a biasing and readout circuit and an amplifier, and optionally also a digitizer, and optionally also a digital processing circuit.

[0030] The magnetic sensors may be integrated in the single substrate or in the main substrate, or may be stacked on the main substrate, or may be integrated in other substrates (also referred to as satellite substrates) located next to the main substrate, and electrically connected thereto, e.g. using a redistribution (RDL) layer, or using bond wires, or in any other suitable manner. The magnetic sensors of the main substrate, but especially those stacked on top of the main substrate, or those of the satellite substrates arranged next to the main substrate, are preferably vertical Hall elements or magnetoresistive elements, e.g. XMR elements.

[0031] Preferably the printed circuit board has at least four layers, or at least six layers.

[0032] Optionally, each sensor device may comprise a plastic or a ceramic package, but that is not absolutely required, and it is also possible to mount the semiconductor substrate on the printed circuit board directly (known in the art as "chip on board").

[0033] In certain embodiments, the lips or protrusions have a periphery which is connected to the PCB over an imaginary line segment, and the remainder of the periphery defines a bulb shape or a bulging shape which is free (i.e. is not connected to the PCB).

[0034] In an embodiment, each lip extends in the first direction (X), preferably by at least 4.0 mm and at most 30 mm, or at most 25 mm, or at most 20 mm, or at most 15 mm.

[0035] In an embodiment, the three lips extend in three perpendicular directions (e.g. as illustrated in FIG. 29 to FIG. 33), preferably by at least 4.0 mm and at most 30 mm, or at most 25 mm, or at most 20 mm, or at most 15 mm.

[0036] In an embodiment, a largest transverse width of the lips or protrusions measured in the second direction (Y), is smaller than a distance between a pair of interconnection portions.

[0037] The lips are sufficiently narrow for being at least partially inserted inside the opening formed between the interconnection portions (e.g. as illustrated in FIG. 1A to FIG. 1C), but sufficiently large for accommodating a sensor device (e.g. a surface mounted packaged chip).

[0038] In an embodiment, each lip has a rectangular shape having a width (e.g. measured in the second direction) smaller than or equal to a distance between a pair of interconnection portions.

[0039] In this case, the shape of the rectangular lip has four sides, one side being connected to the printed board, and three sides being free.

[0040] In an embodiment, each lip has a trapezoidal shape having a largest width (e.g. measured in the second direction) smaller than or equal to a distance between a pair of interconnection portions.

[0041] In an embodiment, each lip has a dome shape or a bulb shape or a semi-elliptical shape with a largest dimension (e.g. measured in the Y-direction), which is smaller than or equal to a distance between a pair of interconnection portions. In an embodiment, each cut-out has a predefined shape selected from the group consisting of: a U-shape, an L-shape, or a rectangular shape, a V-shape, an omega-shape, a dome shape, a bulb shape, a semi-elliptical shape.

[0042] In an embodiment, the printed circuit board further comprises a controller device electrically connected to each of the at least two sensor devices.

[0043] The controller device may be a programmable controller.

[0044] The controller device may have a plurality of inputs connected to the sensor devices for receiving signals indicative of the currents flowing through the conductors, and may have a plurality of outputs connected to a plurality of power switches, and may be configured for selectively activating and deactivating the power switches based on the measured currents, e.g. for driving an electric motor.

[0045] In an embodiment, the printed circuit board further comprises a plurality of power transistors.

[0046] In an embodiment, the current sensor assembly further comprises a plurality of power transistors, which are located on-board (i.e. on the same PCB) or off-board (i.e. not on the same PCB, but on another PCB, e.g. as part of a module connected to the PCB via a connector and a plurality of electrical wires).

[0047] The power transistors may be configured in a half-H bridge or a dual-H-bridge configuration.

[0048] The current sensor assembly may comprise at least four or at least six power transistors.

[0049] The controller may be configured to drive the power transistors (in known manners), based on the measured currents, for example for allowing the current to flow through one or more coils connected to the current sensor assembly.

[0050] In an embodiment, the plurality of magnetic sensors comprise at least two horizontal Hall elements and at least two integrated magnetic concentrators (IMC), e.g. as illustrated in FIG. 8A or FIG. 8B and FIG. 10 to FIG. 14.

[0051] It is an advantage of using horizontal Hall elements and IMC, because they allow to sense inplane magnetic field components (i.e. parallel to the semiconductor substrate), and because the IMC provides "passive amplification" also referred to as "magnetic amplification", e.g. by a factor of about 5, thus increasing the sensitivity and signal-to-noise-ratio (SNR), and also the accuracy.

[0052] In an embodiment (e.g. as illustrated in FIG. 9A), the plurality of magnetic sensors comprise at least two vertical Hall elements oriented with their axis of maximum sensitivity in the first direction (X) and spaced apart (dy) in the second direction (Y).

[0053] In an embodiment (e.g. as illustrated in FIG. 9B), the plurality of magnetic sensors comprise at least two vertical Hall elements oriented with their axis of maximum sensitivity in the second direction (Y) and spaced apart (dx) in the first direction (X).

[0054] In an embodiment, the plurality of magnetic sensors comprise at least two magneto-resistive elements (e.g. AMR, XMR, TMR, GMR elements) oriented with their axis of maximum sensitivity in the first direction (X) and spaced apart (dy) in the second direction (Y). In an embodiment, the plurality of magnetic sensors comprise at least two magneto-resistive elements (e.g. AMR, XMR, TMR, GMR elements) oriented with their axis of maximum sensitivity in the second direction (Y) and spaced apart (dx) in the first direction (X).

[0055] In an embodiment, the plurality of magnetic sensors is configured for measuring a first pair of two magnetic field components (e.g. Bxl, Bx2) oriented in the first direction (e.g. X) at two sensor locations spaced apart in a second direction (e.g. Y) perpendicular to the first direction (e.g. X), and / or the plurality of magnetic sensors may be configured for measuring a second pair of two magnetic field components (e.g. Byl, By2) oriented in the second direction (e.g. Y) at two sensor locations spaced apart in the first direction (e.g. X).

[0056] The semiconductor substrate may be further configured for determining a difference (ABx) between the two magnetic field components of the first pair, and / or for determining a difference (ABy) between the two magnetic field components of the second pair.

[0057] The semiconductor substrate may be further configured for amplifying and / or digitizing one or both of the difference signals (ABx, ABy). The amplified and optionally digitized difference signals may be output.

[0058] The semiconductor substrate may be further configured for determining a first current value based on the first difference (ABx), and / or to determine a second current value based on the second difference (ABy). The first and / or second current value may also be calculated by an external processor connected to the semiconductor substrate, based on one or both of the difference signals (ABx, ABy).

[0059] The semiconductor substrate may be further configured for detecting an error based on a consistency between the first and the second current (e.g. by testing if an absolute difference or a relative difference is smaller than a predefined threshold), and may provide a signal to indicate whether or not an error is detected. A consistency check may also be performed by an external processor, e.g. based on a comparison of the first and the second current value.

[0060] The semiconductor substrate may be further configured for determining a linear combination of the first and the second current value, and for outputting this value as the measured current value. A combined current value may also be determined by an external processor, e.g. based on a linear combination, or a sum, or an average of the first and the second current value.

[0061] In an embodiment, the plurality of magnetic sensors comprise at least four horizontal Hall elements and at least two integrated magnetic concentrators, e.g. as illustrated in FIG. 8A or FIG. 8B.

[0062] In an embodiment, the plurality of magnetic sensors comprise at least two horizontal Hall elements and at least two integrated magnetic concentrators (IMC), e.g. as illustrated in FIG. 10.

[0063] In an embodiment, the plurality of magnetic sensors comprise at least four horizontal Hall elements and at least four integrated magnetic concentrators (IMC), e.g. as illustrated in FIG. 11.

[0064] In an embodiment, the plurality of magnetic sensors comprise at least eight horizontal Hall elements and at least four integrated magnetic concentrators, e.g. as illustrated in FIG. 12 or FIG. 14. In an embodiment, the plurality of magnetic sensors comprise at least eight horizontal Hall elements and at least eight integrated magnetic concentrators (IMC), e.g. as illustrated in FIG. 13.

[0065] In an embodiment, the current sensor assembly comprises a first conductor for conducting a first current, and a first sensor device arranged in an opening of the first conductor for measuring said first current; and comprises a second conductor for conducting a second current, and a second sensor device arranged in an opening of the second conductor for measuring said second current; and comprises a third conductor for conducting a third current, and a third sensor device arranged in an opening of the third conductor for measuring said third current.

[0066] Such an assembly may for example be a three-phase current sensor system, in which the three currents are substantially 120° phase shifted.

[0067] In an embodiment, the plurality of conductors are spaced apart in the second direction (Y), and the two interconnection portions of each individual conductor are spaced apart in the second direction (Y), and the lips of the printed circuit board extend in the first direction (X), and are spaced apart in the second direction (Y).

[0068] An example of such an assembly is illustrated in FIG. 16A to FIG. 17C, or in FIG. 24. In these examples, three lips extend from a single virtual line, but that is not absolutely required.

[0069] As can be seen in the simulation of FIG. 20, this current sensor assembly is very much capable of accurately measuring currents up to a relatively high frequency, e.g. up to about 1500 Hz, or up to about 1000 Hz, or up to about 500 Hz, or up to about 100 Hz, without requiring a magnetic shielding to prevent cross-talk between the different phases.

[0070] It is a major advantage of this assembly that the current can be measured in a manner which is highly insensitive to cross-talk, even without using a magnetic shielding, and even without using an "inverse coupling matrix" or the like.

[0071] Furthermore, if four magnetic field components are measured, and if two difference signals (e.g. ABx and ABy) are derived therefrom, it is possible to detect and optionally output an error signal by performing a consistency test of these two difference signals.

[0072] In an embodiment, the plurality of conductors are spaced apart in the first direction (X), and the two interconnection portions of each individual conductor are spaced apart in the second direction (Y); and the lips of the printed circuit board extend in the first direction (X), and are spaced apart in the first direction (X).

[0073] An example of such an assembly is illustrated in FIG. 18A to FIG. 18B, and in FIG. 19A to FIG. 19B, and in FIG. 22A to FIG. 22B, and in FIG. 28. In these examples, a central line segment of each of the three lips are located on a single virtual line, but that is not absolutely required.

[0074] As can be seen in the simulation of FIG. 20, this current sensor assembly is very much capable of accurately measuring currents up to a relatively high frequency, e.g. up to about 1500 Hz, or up to about 1000 Hz, or up to about 500 Hz, or up to about 100 Hz, without requiring a magnetic shielding to prevent cross-talk between the different phases.

[0075] It is a major advantage of this assembly that the current can be measured in a manner which is highly insensitive to cross-talk, even without using a magnetic shielding, and even without using an "inverse coupling matrix" or the like. But of course, certain embodiments of the present invention may use an "inverse coupling matrix" to further reduce the cross-talk.

[0076] Furthermore, if four magnetic field components are measured, and if two difference signals (e.g. ABx and ABy) are derived therefrom, it is possible to detect and optionally output an error signal by performing a consistency test of these two difference signals.

[0077] In an embodiment, each of the sensor devices is packaged in a surface mounted package.

[0078] In an embodiment, each of the sensor devices is packaged in an SOIC-package, or a QFN package, or a DFN package or a SON Package.

[0079] The abbreviations stand for QFN (Quad Flat No Lead package), DFN (Dual Flat No Lead package), SON (Small Outline No-Lead package). Using a package without long elongated leads offers the advantage that it may offer better isolation (e.g. less capacitive coupling, less interferences) between the busbar and the electrical leads, resulting in a higher accuracy.

[0080] According to a second aspect, the present invention also provides a printed circuit board comprising at least two cut-outs and at least two lips or protrusions accommodating at least two sensor devices, each sensor device having at least four electrical contacts (e.g. pins or elongated leads) connected to the printed circuit board; each sensor device being or comprising a semiconductor substrate oriented parallel to the printed circuit board; each sensor device comprising a plurality of magnetic sensors configured for measuring at least two magnetic field components oriented parallel to the semiconductor substrate.

[0081] It is contemplated that the PCB of the second aspect can have any or all of the characteristics of the PCB used in the first aspect, and vice versa. For example, the sensor devices may comprise horizontal Hall elements and / or IMC as described above; the PCB may comprise a controller device and / or power transistors, etc. Only a few of these combinations are explicitly repeated next.

[0082] In an embodiment, the lips have a rectangular shape or a trapezoidal shape or a triangular shape or a dome shape or a bulb shape or a semi-elliptical shape, and the cut-outs have a predefined shape selected from the group consisting of: a U-shape, an L-shape, a rectangular shape, a V-shape, an omegashape, a dome shape, a bulb shape, a semi-elliptical shape.

[0083] In an embodiment, the printed circuit board further comprises a controller device (e.g. comprising a programmable processor) electrically connected to the at least two sensor devices.

[0084] In an embodiment, the printed circuit board further comprises at least two power transistors connected to said controller. In an embodiment, each of the sensor devices comprise a plurality of magnetic sensors, and a biasing and readout circuit; and the lips extend in a first direction (X); and each of the sensor devices is configured (i) for measuring two first magnetic field components (e.g. Bxl, Bx2) oriented in the first direction (X) at two sensor locations (e.g. A, B) spaced apart in a second direction (Y) parallel to the printed circuit board, perpendicular to the first direction (X); and / or (ii) for measuring two second magnetic field components (e.g. Byl, By2) oriented in the second direction (Y) at two sensor locations (e.g. C, D) spaced apart in the first direction (X).

[0085] In an embodiment, each of the sensor devices comprise a plurality of magnetic sensors, and a biasing and readout circuit; and the lips extend in three different directions including a first direction (X); and each of the sensor devices is configured (i) for measuring two first magnetic field components (e.g. Bxl, Bx2) oriented in the first direction (X) at two sensor locations (e.g. A, B) spaced apart in a second direction (Y) parallel to the printed circuit board, perpendicular to the first direction (X); and / or (ii) for measuring two second magnetic field components (e.g. Byl, By2) oriented in the second direction (Y) at two sensor locations (e.g. C, D) spaced apart in the first direction (X). An example of such a PCB is illustrated in FIG. 29 to FIG. 33.

[0086] In an embodiment, the sensor device has a semiconductor substrate with a front side (or "active side" or "device side") and a back side, and the semiconductor device is mounted with its front side oriented towards the printed circuit board, e.g. as described in EP3992653(A1), incorporated herein by reference. The semiconductor substrate may be mounted below the leads of the package. This type of sensor device may be referred to as "die down current sensor". The sensor device may have an electrically conductive die paddle inside the package situated on top of (or above) the back side of the semiconductor substrate, and the PCB may have a grounded area underneath the semiconductor substrate, such that the semiconductor substrate is situated between two grounded conductive areas, thereby reducing capacitive coupling (e.g. related to dV / dt) between the busbar and the semiconductor substrate. As far as is known to the inventors, such a current sensor device is not yet used inside an opening of a busbar.

[0087] According to a third aspect, the present invention also provides a power invertor comprising a current sensor assembly according to the first aspect, and / or comprising a PCB according to the second aspect.

[0088] In an embodiment, the power convertor comprises only one PCB, in other words, the PCB with protrusions and lips and sensor devices also contains all other electronics of the power convertor, e.g. a power controller, power switches, etc.

[0089] Particular and preferred aspects of the present invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiment(s) described hereinafter.

[0090] Brief description of the drawings

[0091] FIG. 1A to FIG. 1C show an illustrative example of an arrangement of an electrical conductor having an opening, and a sensor device mounted on a lip of a PCB, which can be inserted at least partially inside said opening, as can be used in embodiments of the present invention.

[0092] FIG. 1A (left) shows a side view of the PCB and a cross-sectional view of the conductor before insertion, FIG. 1A (right) shows a front view;

[0093] FIG. IB (left) shows a side view of the PCB and a cross-sectional view of the conductor after insertion, FIG. IB (right) shows a front view;

[0094] FIG. 1C shows a perspective view of FIG. 1A.

[0095] FIG. ID shows a variant of FIG. 1C, showing that the sensor device has a semiconductor substrate which is parallel to a (preferably rectangular) cross-section of the interconnection portions.

[0096] FIG. IE shows an example of a busbar with a "zig-zag" (formed by two cut-outs starting from opposite sides of the busbar), and with an opening in the portion between the cut-outs.

[0097] FIG. 2 to FIG. 4 give an impression of magnetic field lines induced by a current flowing through the interconnection portions of FIG. ID, as can be sensed in the virtual plane XY.

[0098] FIG. 2 shows that two magnetic field components Bxl, Bx2 can be measured at two sensor locations A, B spaced apart in the Y-direction, and that a current value can be determined based on a difference ABx between these magnetic field components;

[0099] FIG. 3 shows that two magnetic field components Byl, By2 can be measured at two sensor locations C, D spaced apart in the X-direction, and that a current value can be determined based on a difference ABy between these magnetic field components;

[0100] FIG. 4 shows a combination of FIG. 2 and FIG. 3, wherein four magnetic field components are measured, from which two magnetic field differences and / or two current values can be derived.

[0101] FIG. 5 shows an illustrative example of possible sensor locations A, B, C, D for an illustrative packaged device having a rectangular shape, oriented with its long side along the X-direction.

[0102] FIG. 6 shows another illustrative example of possible sensor locations A, B, C, D for an illustrative packaged device having a rectangular shape, oriented with its long side along the Y-direction.

[0103] FIG. 7 shows an illustrative example of a package having contact pins without elongated leads, as may be used in embodiments of the present invention.

[0104] FIG. 8A to FIG. 14 show illustrative examples of sensor structures that may be used in embodiments of the present invention, but the present invention is not limited hereto.

[0105] FIG. 15A and FIG. 15B show a variant of FIG. 1A and FIG. IB, illustrating that the electrical conductor may furthermore have an L-shape. FIG. 16A to FIG. 16C show an illustrative example of a current sensor assembly comprising: three busbars each having an opening, and comprising a single PCB having three lips (or protrusions), and having three sensor devices mounted on said lips; wherein the sensor devices are at least partially inserted in said openings in a manner similar to FIG. IB.

[0106] FIG. 16A shows a front view of the current sensor arrangement;

[0107] FIG. 16B shows a top view before insertion;

[0108] FIG. 16C shows a top view after insertion.

[0109] FIG. 17A to FIG. 17C show a variant of FIG. 16A to FIG. 16C, where the PCB has an overall rectangular shape with three U-shaped cut-outs complementary to the shape of the lips, each U-shaped cut-out having two leg portions and a bridge portion, and the three lips of the PCB are situated between respective leg portions.

[0110] FIG. 18A and FIG. 18B show a variant of FIG. 16B and FIG. 16C, wherein the busbars are rotated over 90° about the Z-axis, and the PCB has three L-shaped cut-outs.

[0111] FIG. 19A and FIG. 19B show a variant of FIG. 18A and FIG. 18B, where the PCB has an overall rectangular shape with three U-shaped cut-outs.

[0112] FIG. 20 shows a graph with simulation results of current measurements for the sensor arrangement of FIG. 18B, without a magnetic shield, and without matrix cross-talk correction calculations, taking into account mechanical mounting tolerances.

[0113] FIG. 21A to FIG. 21H show examples of printed circuit boards with three sensor devices mounted thereon, as embodiments of the present invention.

[0114] FIG. 22 shows an illustrative example of a current sensor assembly comprising three busbars and a single PCB (e.g. similar to that of FIG. 21F) as an embodiment of the present invention.

[0115] FIG. 23 shows a high-level block-diagram of an electrical circuit that may be implemented on printed circuit boards proposed by the present invention.

[0116] FIG. 24 shows another illustrative example of a current sensor assembly according to an embodiment of the present invention.

[0117] FIG. 25 shows the busbars of FIG. 24 in perspective view.

[0118] FIG. 26 shows the busbars of FIG. 24 and FIG. 25 in top view.

[0119] FIG. 27 shows the busbars of FIG. 24 to FIG. 26 in side view.

[0120] FIG. 28 shows another illustrative example of a current sensor assembly according to an embodiment of the present invention.

[0121] FIG. 29 shows another illustrative example of a current sensor assembly according to an embodiment of the present invention. FIG. 30 to FIG. 33 show illustrative examples of printed circuit boards that can be used in the current sensor assembly of FIG. 29.

[0122] The drawings are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Any reference signs in the claims shall not be construed as limiting the scope. In the different drawings, the same reference signs refer to the same or analogous elements.

[0123] Detailed description of illustrative embodiments

[0124] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0125] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0126] Moreover, the terms top, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other orientations than described or illustrated herein.

[0127] It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0128] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0129] Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0130] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0131] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

[0132] The same or similar reference numerals (modulo 100) may be used to indicate same or similar structural features in different embodiments.

[0133] In this document, unless explicitly mentioned otherwise, the term "magnetic sensor device" or "sensor device" refers to a device comprising at least one "magnetic sensor" or at least one magnetic "sensor element", preferably integrated in a semiconductor substrate. The sensor device may be comprised in a package, also called "chip", although that is not absolutely required.

[0134] In this document, the term "sensor element" or "magnetic sensor element" or "magnetic sensor" can refer to a component or a group of components or a sub-circuit or a structure capable of measuring a magnetic quantity, such as for example a magneto-resistive (MR) element, an AMR element, a GMR element, a TMR element, an XMR element, a horizontal Hall plate, a vertical Hall plate, a Wheatstone-bridge containing at least one (but preferably four) magneto-resistive elements, etc. or combinations hereof.

[0135] In embodiments of the present invention, the term "magnetic sensor" or "magnetic sensor structure" may refer to an arrangement comprising one or more integrated magnetic concentrators (IMC), also known as "integrated magneticflux concentrators", and one or more horizontal Hall elements arranged near the periphery of the IMC, for example a disk shaped IMC with one, or two or four horizontal Hall elements arranged near a periphery of the IMC.

[0136] Embodiments of the present invention are typically described using an orthogonal coordinate system which is fixed to the semiconductor substrate, and having three axes X, Y, Z, where the X and Y axis are parallel to the substrate, and the Z-axis is perpendicular to the substrate. In this document, the expression "in-plane component of a magnetic field vector" and "projection of the magnetic field vector in the sensor plane" mean the same. If the sensor device is or comprises a semiconductor substrate, this also means a "magnetic field component parallel to the semiconductor plane". These components are typically referred to herein as Bx, By.

[0137] In this document, the expression "out-of-plane component of a magnetic field vector" and "Z component of the vector" and "projection of the vector on an axis perpendicular to the sensor plane" mean the same. This component is typically referred to herein as Bz.

[0138] In this document, the expression "spatial derivative" or "derivative" or "spatial gradient" or "gradient" are used as synonyms. If the order of the derivative is not explicitly mentioned, a first order gradient is meant, unless clear from the context otherwise. In the context of the present invention, the gradient is typically determined as a difference between two values measured at two locations spaced apart along a certain direction. In theory the gradient is typically calculated as the difference between two values divided by the distance between the sensor locations (e.g. dx or dy), but in practice the division by said distance is often omitted, because the measured signals need to be scaled anyway. Hence, in the context of the present invention, the expression "magnetic field difference" and "magnetic field gradient" can be used interchangeably.

[0139] In this application, horizontal Hall plates are typically referred to by Hl, H2, etc., signals obtained from horizontal Hall plates are typically referred to by hl, h2, etc., vertical Hall plates are typically referred to by VI, V2, etc., and signals from vertical Hall plates are typically referred to by vl, v2, etc.

[0140] In this document, sensor locations relative to the busbar may be referred to by the letters A, B, C, D, for example as illustrated in FIG. 5 or FIG. 6. The locations A and B are preferably located in a symmetry plane of the interconnection portions parallel to the YZ plane and are spaced apart by a distance dy. The locations C and D are preferably located in another symmetry plane of the interconnection portions parallel to the XZ plane and are spaced apart by a distance dx.

[0141] With "width of a conductor or busbar" is meant an outer dimension of said conductor or busbar measured in a direction substantially perpendicular to the direction of current flow, unless it is clear from the context that something else is meant.

[0142] In the context of this document, the terms "lip" and "protrusion" mean the same, and they refer to an extending portion or a bulging portion of a printed circuit board, e.g. an elongated rectangular or trapezoidal portion, but other shapes are also possible, such as e.g. a triangular shape or a semi-elliptical shape, or an omega-shape, etc.

[0143] The present invention relates to current sensor assemblies comprising a plurality of electrical conductors (e.g. busbars) with openings, and comprising a printed circuit board with a plurality of sensor devices positioned at least partially in these openings, (for example the current sensor assembly shown in FIG. 16A to FIG. 19B,or FIG. 22B, or FIG. 24, or FIG. 28 or FIG. 29).

[0144] The present invention also relates to a printed circuit board for use in such a current sensor assembly, wherein the PCB comprises a plurality of cut-outs, and a plurality of lips or protrusions, and a plurality of sensor devices mounted on said lips, (for example the PCB shown in FIG. 16B, FIG. 17B, FIG. 18A, FIG. 19A, FIG. 21A to FIG. 21H, FIG. 22A, FIG. 24, FIG. 28 to FIG. 33.

[0145] In order to better appreciate the principles of the present invention, certain aspects will first be explained for a single sensor device 30 arranged at least partially inside an opening 25 of a single electrical conductor 20.

[0146] Referring to the Figures.

[0147] FIG. 1A shows an illustrative example of an electrical conductor 20 having a first main portion 21 and a second main portion 22, and two interconnection portions 23 and 24 between the main portions. The two interconnection portions 23, 24 are oriented in parallel to each other, and are spaced apart from each other so as to create an opening 25 between them.

[0148] FIG. 1A also shows a sensor device 30 mounted on a printed circuit board (PCB) 10, or actually on a portion of the PCB, referred to herein as lip or protrusion 11, which in FIG. 1A has a rectangular shape with a width Wil and a length Lil, but other shapes are also possible, e.g. a trapezoidal shape.

[0149] The conductor 20 has a width W20 (see FIG. 1C), and a thickness T20. The width W20 is typically a value in the range from 5 to 30 mm. The thickness T20 is typically a value in the range from 0.5 to 10 mm. The opening 25 may have a width W25 in the range from 1.0 to 15.0 mm, or from 3.0 mm to 15.0 mm, or from 4.0 mm to 15.0 mm, or from 5.0 mm to 15.0 mm, or from 3.0 mm to 12.0 mm. The opening 25 may have a height H25 in the range from 1.0 to 15.0 mm, or from 3.0 mm to 15.0 mm, or from 4.0 mm to 15.0 mm, or from 5.0 mm to 15.0 mm, or from 7.0 mm to 15.0 mm, or from 3.0 mm to 12.0 mm.

[0150] The first interconnection portion 23 has a width w23 (see FIG. IB), and the second interconnection portion has a second width w24, which may be smaller than w23 or larger than w23 but is preferably equal to w23. The widths w23, w24 of the interconnection portions 23, 24 are preferably at least a factor 3.0 smaller than the width W20 of the main portions 21, 22, (or written mathematically: preferably w23 / w20 >3.0), more preferably at least a factor of at least 4.0.

[0151] In the example of FIG. 1A to FIG. 1C, the sum (w23+w25+w24) is equal to the width w20 of the main portions 21, 22, but that is not absolutely required for the invention to work, and in other embodiments, said sum is larger than w20 or smaller than w20, depending on the positions (in the Y- direction) of the interconnection portions 23, 24 with respect to the main portions 21, 22.

[0152] As can be seen, the lip 11 is relatively narrow such that the lip 11 can be inserted inside said opening 25 and such that the sensor device 30 which is mounted thereon, is situated at least partially inside the opening 25 after the insertion. The sensor device 30 may for example occupy an area of about 2.0 mm x 2.0 mm to about 10.0 x 10.0 mm on the printed circuit board (PCB), or from 4.0 mm2to 100.0 mm2, or from 9.0 mm2to 81.0 mm 7 , or from 15.0 mm 7 to 65.0 mm 7 , or from 20 mm 7 to 50 mm 7 , or from 20 mm 7 to 40 mm 7 , or from 30 mm2to 50 mm2, but the present invention is not limited thereto.

[0153] The sensor device 30 comprises a semiconductor substrate 31 (not shown in FIG. 1A, but see e.g. FIG. ID) which is oriented in parallel with the surface of the printed circuit board 10. An orthogonal coordinate system X, Y, Z is connected to the lip 11, such that the lip 11 has a length Lil extending in the X-direction, and has a width wll extending in the Y-direction. The semiconductor substrate 31 is oriented in parallel with the printed circuit board 10, hence is parallel to the XY-plane. The interconnection portions 23 and 24 extend in the Z-direction, perpendicular to the semiconductor substrate. The currents flowing through the interconnection portions 23, 24 also flow in the Z-direction.

[0154] FIG. 1A shows the PCB 10 and the conductor 20 before insertion of the lip 11 with the sensor device 30 into the opening 25. FIG. IB shows the PCB and the conductor after insertion. The left part of FIG. 1A and FIG. IB shows a side view or a cross-sectional view. The right parts of FIG. 1A and FIG. IB show a front view. FIG. 1C shows a perspective view of FIG. 1A.

[0155] FIG. ID shows another perspective view of FIG. 1A and FIG. IB, showing that the sensor device 30 has a semiconductor substrate 31 which is parallel to a cross-sectional area 26, 27 of the interconnection portions 23, 24 of the electrical conductor 20. Or stated in other words, the current flowing through the interconnection portions 23, 24 flows in the Z-direction, and the semiconductor substrate 31 is oriented perpendicular to the Z-direction.

[0156] Preferably, the first interconnection portion 23 has a first cross-sectional area Al, and the second interconnection portion 24 has a second cross-sectional area A2 in a plane perpendicular to the Z-direction, and preferably Al is substantially equal to A2.

[0157] Preferably, the two interconnection portions 23, 24 have a rectangular cross-section, and extend linearly over a distance of at least 5 mm, or at least 7 mm, or at least 10 mm.

[0158] FIG. IE shows an example of a busbar 20 with a "zig-zag" formed by two cut-outs 28, 29 starting from opposite sides of the busbar, and having an opening 25 in the portion between the cut-outs 28, 29. The opening 25 is formed between two parallel interconnection portions 23, 24. Current is flowing in these interconnection portions in the Z-direction. A semiconductor substrate 31 is arranged between the interconnection portions 23, 24, and is oriented parallel to the XY-plane, perpendicular to the Z- direction. The semiconductor substrate 31 may be part of a sensor device 30, e.g. a packaged sensor device, mounted on a printed circuit board 10, e.g. on a lip 11 thereof. The lip extends in the X-direction, and can be inserted at least partially inside the opening 25. The sensor arrangement of FIG. IE can be seen as a special case or as a variant of the sensor assembly of FIG. 1A to FIG. ID. As can be appreciated, the overall current (to be measured) flows through this busbar in the Y-direction, but the cut-outs 28, 29 and the opening 25 formed between the interconnection portions 23, 24 force the current to flow through the interconnection portions 23, 24 in the Z-direction, and a magnetic field generated by these currents is measured using magnetic sensor elements embedded in the semiconductor substrate 31, as will be explained further.

[0159] FIG. 2 to FIG. 4 give a qualitative impression of magnetic field lines induced by a current flowing through the interconnection portions 23, 24 of FIG. ID, seen in a virtual plane XY, perpendicular to the direction Z in which the currents flow. At any moment in time, the two currents flowing through the interconnection portions 23, 24 flow in the same direction. In practice these currents are AC currents, meaning they change over time. The drawings of FIG. 2 to FIG. 4 give an impression of the magnetic field lines generated by these currents when flowing in the positive Z-direction.

[0160] According to underlying principles of the present invention, the currents flowing through the interconnection portions 23, 24, and thus also the current flowing through the entire conductor (e.g. busbar) 20, are preferably determined in one or both of the following manners:

[0161] (i) based on a magnetic field difference ABx between two magnetic field components Bxl, Bx2 oriented in the X-direction, measured at two sensor locations A, B which are spaced apart in the Y- direction by a distance "dy" The value of dy is smaller than the value of W25. The distance dy may for example be a value in the range from about 1.0 to about 15.0 mm, or from 1.0 to 10.0 mm, or from 2.0 mm to 15.0 mm, or from 3.0 mm to 15.0 mm, or from 3.0 mm to 12.0 mm, or from 3.0 mm to 9.0 mm, or from 5.0 to 12.0 mm, or from 6.0 to 11.0 mm, or from 7.0 to 10.0 mm. As mentioned above, the locations A and B are preferably located in a symmetry plane of the interconnection portions 23, 24 parallel to the YZ-plane. The locations A and B are preferably chosen symmetrically with respect to a center of the opening 25.

[0162] (ii) based on a magnetic field difference ABy between two magnetic field components Byl, By2 oriented in the Y-direction, measured at two sensor locations C, D which are spaced apart in the X- direction by a distance "dx". The value of dx may be larger than, smaller than, or equal to T20. The distance dx may be a value in the range from about 1.0 to about 25.0 mm, or from 2.0 mm to 20.0 mm, or from 3.0 mm to 25.0 mm, or from 3.0 mm to 20.0 mm, or from 2.0 mm to 15.0 mm, or from 3.0 to 10.0 mm. As mentioned above, the locations C and D are preferably located in a symmetry plane of the interconnection portions 23, 24 parallel to the XZ-plane. The locations C and C are preferably chosen symmetrically with respect to a center of the opening 25.

[0163] A magnetic field difference or gradient is highly insensitive to a (constant) disturbance field. By choosing the locations A and B on the one hand, and C and D on the other hand substantially symmetrical w.r.t. the center of the opening, the result is also highly insensitive to position offset of the semiconductor substrate 31 in the Y-direction and / or the X-direction, because for example, if the substrate is slightly shifted to the left in FIG. 4, the component Bxl will slightly increase and Bx2 will slightly decrease by substantially the same amount, such that the difference ABx will only marginally change. Likewise, a small shift of the semiconductor substrate on which the sensor locations A to D are located in the X-direction of FIG. 4 will only have a minor impact on ABy. Thus a current value derived from ABx and / or ABy is highly insensitive to mounting offset of the sensor device 30.

[0164] FIG. 2 shows that two magnetic field components Bxl, Bx2 measured at the sensor locations A, B are both oriented in the X-direction, and have opposite directions. Hence a difference ABx between these magnetic field components would typically double the value of a single measurement, and thus provide a larger signal-to-noise ratio (SNR) than a single measurement. The difference ABx may also be referred to as the magnetic field gradient of Bx along the Y-direction, written as dBx / dy, even though in practice a division by the distance "dy" is typically omitted, because the signals obtained from the magnetic sensing elements or sensing structure (e.g. Hall elements and / or Wheatstone bridge) need to be scaled (e.g. amplified) anyway. A first value for the current flowing through the interconnection portions 23, 24 can then be determined as a value proportional to the difference ABx, e.g. in accordance with the formula: l2=K2*ABx, where K2 is a predefined constant.

[0165] FIG. 3 shows that two magnetic field components Byl, By2 measured at the sensor locations C, D are both oriented in the Y-direction, and have opposite directions. Hence a difference ABy between these magnetic field components would typically double the value of a single measurement, and thus provide a larger signal-to-noise ratio (SNR) than a single measurement. The difference ABy may also be referred to as the magnetic field gradient of By along the X-direction, written as dBy / dx, even though in practice a division by the distance "dx" is typically omitted, because the signals obtained from the magnetic sensing elements or sensing structure (e.g. Hall elements and / or Wheatstone bridge) need to be scaled (e.g. amplified) anyway. A second value for the current flowing through the interconnection portions 23, 24 can then be determined as a value proportional to the difference ABy, e.g. in accordance with the formula: l3=K3*ABy, where K3 is a predefined constant.

[0166] FIG. 4 shows a combination of FIG. 2 and FIG. 3, wherein four magnetic field components Bxl, Bx2, Byl, By2 are measured, two oriented in the X-direction, and two oriented in the Y-direction, and wherein two pairwise differences ABx and ABy are determined, from which a first current value 12, and a second current value 13 can be derived, and / or from which an overall current value 14 can be derived, e.g. as a linear combination of 12 and 13, e.g. in accordance with the formula: I4=wl*l2 + w2*l3, where wl and w2 are predefined constants; or as a linear combination of ABx and ABy, e.g. in accordance with the formula: l4=K4*ABx + K5*ABy, wherein K4 and K5 are predefined constants. The values of one or more of the predefined constants K2, K3, K4, K5, wl, w2 may be determined by simulation or by a calibration test, and may be stored in a non-volatile memory of the sensor device itself, and / or in a non-volatile memory of a controller 41 connected to the sensor device (not shown in FIG. 4 but see e.g. FIG. 23).

[0167] FIG. 5 shows an illustrative example of possible sensor locations A, B, C, D for an illustrative packaged device 30 having an overall rectangular shape, oriented with its long side along the X-direction.

[0168] Each of the sensor locations A, B, C, D is located on a semiconductor substrate 31 having a rectangular shape with a length L31 and a width w31. In embodiments of the present invention, the packaged sensor device 30 comprising the semiconductor substrate 31 is mounted on a printed circuit board 10, more specifically on a lip 11 thereof (not shown in FIG. 5, but see e.g. FIG. 1A to FIG. IE). In other embodiments of the present invention (not shown), the semiconductor substrate 31 is not incorporated in a packaged device, but is mounted on the PCB directly.

[0169] In the example shown in FIG. 5, the length L31 of the semiconductor substrate 31 is measured in the X-direction, and (in this example) is larger than the thickness T20 of the interconnection portions 23, 24, but that is not absolutely required for the invention to work, and in other embodiments L31 may be substantially equal to T20, or L31 may be smaller than T20.

[0170] In the example shown in FIG. 5, the width w31 of the semiconductor substrate 31 is measured in the Y-direction, and is smaller than the width w25 of the opening 25 between the interconnection portions 23, 24.

[0171] The distance "dx" between the sensor locations C and D may be larger than, substantially equal to, or smaller than the thickness T20 of the interconnection portions 23, 24. The distance "dy" between the sensor locations A and B is smaller than the width w25 of the opening 25 between the two interconnection portions 23, 24.

[0172] The ratio (dy / W25) may be a value in the range from 40% to 95%, but the present invention is not limited hereto.

[0173] The ratio (dx / T20) may be a value in the range from 50% to 250%, or from 70% to 200%, but the present invention is not limited hereto.

[0174] The ratio (dx / W20) may be a value in the range from 50% to 130%, or from 70% to 110%, but the present invention is not limited hereto.

[0175] The ratio (dx / W25) may be a value in the range from 60% to 140%, but the present invention is not limited hereto.

[0176] If four sensor locations A, B, C, D are present (but as mentioned above, that is not absolutely required, and only two sensor locations are sufficient), the value of dy may be substantially equal to dx, or may be larger than dx, or may be smaller than dx. It is an advantage of orienting the semiconductor substrate 31 parallel to the XY-plane, (e.g. by mounting the semiconductor substrate directly on the PCB without a package, or by using an SMD ("surface mount") package, or by using a package without elongated leads, etc.) because by doing so, the electrical contacts, e.g. the package pins (if any) are located in a plane parallel to the XY-plane, which helps reduce so called "di / dt" interference, (inter alia) because coils formed by the elongated leads (if any) are located "in the plane XY", and thus do not form a significant area that picks-up a time-varying flux caused by the currents flowing through the interconnection portions 23, 24. This is especially important if the semiconductor substrates contain magnetic sensors, and preferably also a biasing and readout circuit, and preferably also an amplifier, but no digitizer (e.g. ADC), because the amplified analog signals would be disturbed when leaving the semiconductor substrate.

[0177] In the example shown in FIG. 5, the illustrative package has eight pins, but that is not absolutely required, and other packages having at least four contacts or leads or pins can also be used. In fact, it is not absolutely required that the sensor device has a plastic or a ceramic package, and the invention will also work if the semiconductor substrate 31 is directly mounted on the PCB.

[0178] In a variant of FIG. 5, the semiconductor substrate 31 would have only two sensor locations A and B, but not C and D. In another variant, the semiconductor substrate 31 would have only two sensor locations C and D, but not A and B. Depending on which sensor locations are used, the formulas of FIG. 2 to FIG. 4 can be used to determine the current flowing through the conductor 20.

[0179] FIG. 6 shows another illustrative example of possible sensor locations A, B, C, D for the same illustrative package as shown in FIG. 5, but oriented with its long side along the Y-direction. Everything else described above is also applicable here.

[0180] The main purpose of FIG. 5 and FIG. 6 is to illustrate that the sensor locations A and B (if used) are always situated inside the space defined by the opening 25 between the two interconnection portions 23, 24, while the sensor locations C and D (if used) may be located inside or outside said space (e.g. if dx>T20).

[0181] FIG. 5 and FIG. 6 show a surface mounted package having a rectangular shape, but square packages can also be used.

[0182] FIG. 7 shows an example of a package having contact pins without elongated leads, as may be used in embodiments of the present invention. Suitable packages may include for example SOI-packages, QFN-packages (Quad Flat No Lead package), DFN-packages (Dual Flat No Lead package), SON-packages (Small Outline No-Lead package), but the present invention is not limited hereto.

[0183] Using a package without long elongated leads offers the advantage that it may offer better isolation (e.g. less capacitive coupling, less interferences) between the busbar and the electrical leads, resulting in a higher accuracy. It is also possible to use a sensor device having a package with leads, wherein the semiconductor substrate is mounted below the leads of the package. The semiconductor substrate may have a front side (or "active side" or "device side") and a back side, and the semiconductor device is preferably mounted with its front side or "active side" oriented towards the printed circuit board, e.g. as described in EP3992653(A1), incorporated herein by reference in its entirety. This type of sensor device may be referred to herein as a "die down current sensor". The sensor device may have an electrically conductive die paddle inside the package situated on top of (or above) the back side of the semiconductor substrate, and the PCB may have a grounded area underneath the semiconductor substrate 31, such that the semiconductor substrate 31 is situated between two grounded conductive areas, thereby reducing capacitive coupling (e.g. related to dV / dt) between the busbar and the semiconductor substrate, resulting in less disturbance, and thus a more accurate measurement.

[0184] FIG. 8A to FIG. 14 show illustrative examples of sensors or sensor structures that can be used in embodiments of the present invention, but the present invention is not limited hereto, and other sensors or sensor structures may also be used, such as sensor structures comprising one or more magneto-resistive (MR) elements.

[0185] FIG. 8A shows a semiconductor substrate 831 with two magnetic sensor structures SI, S2, spaced apart in the Y-direction by a distance dy. The first magnetic sensor structure SI comprises an integrated magnetic concentrator disk IMC1 and two horizontal Hall elements Hl, H2 located near a periphery of IMC1. The horizontal Hall elements Hl and H2 are 180° spaced apart, and are located on a virtual line parallel to the X-direction. The second magnetic sensor structure S2 comprises an integrated magnetic concentrator disk IMC2 and two horizontal Hall elements H3, H4 located near a periphery of IMC2. The horizontal Hall elements H3 and H4 are 180° spaced apart, and are located on a virtual line parallel to the X-direction. The centers of IMC1 and IMC2 are located on a virtual line parallel to the Y- axis, and they are spaced apart by a distance "dy". The magnetic concentrators IMC1, IMC2 may have a diameter in the range from 50 to 500 pm, or from 100 to 400 pm, or from 150 to 300 pm; and a thickness in the range from 10 to 50 pm or from 15 to 40 pm, or from 20 to 25 pm.

[0186] When the semiconductor substrate 831 is used in a current sensor assembly comprising a conductor 20 with an opening (e.g. as illustrated in FIG. 1A to FIG. IE), and is positioned and oriented as illustrated in FIG. 2 and FIG. 5, meaning that the sensor structure SI is situated at sensor location A, and that the sensor structure S2 is situated at sensor location B, then the following formulas can be used to determine the current:

[0187] Bxl=(hl-h2) [1]

[0188] Bx2=(h3-h4) [2]

[0189] ABx=(Bxl-Bx2) [3] l8a=K8a*ABx [4] where Bxl, Bx2 are magnetic field components oriented in the first direction X, and hl, h2, h3, h4 are signals obtained from a first, second, third and fourth horizontal Hall element Hl, H2, H3, H4, and wherein ABx is a magnetic field difference between these magnetic field components, and K8a is a predefined constant.

[0190] FIG. 8B shows a variant of FIG. 8A, showing the same or a similar semiconductor substrate 831 as FIG. 8A, but rotated by 90° about the Z-axis. When this semiconductor substrate is positioned and oriented relative to a conductor 20 in a manner similar to FIG. 3 and FIG. 6, meaning that the sensor structure SI is situated at sensor location C, and that the sensor structure S2 is situated at sensor location D, the distance between them is referred to as dx, and the following formulas can be used to determine the current:

[0191] Byl=(hl-h2) [5]

[0192] By2=(h3-h4) [6]

[0193] ABy=(Byl-By2) [7] l8b=K8b*ABy [8] where Byl, By2 are magnetic field components oriented in the second direction Y, and hl, h2, h3, h4 are signals obtained from a first, second, third and fourth horizontal Hall element Hl, H2, H3, H4, and wherein ABy is a magnetic field difference between these magnetic field components, and K8b is a predefined constant.

[0194] The predefined constant K8a of FIG. 8A and K8b of FIG. 8B may be determined by simulation or by a calibration procedure or in any other suitable way, and may be stored in a non-volatile memory (if present) of the semiconductor substrate 31, and / or in a non-volatile memory implemented on a second substrate contained in the sensor device 30, and / or in a non-volatile memory of another device connected to the sensor device 30, e.g. a controller device 41 (if present) which is preferably also present on the same printed circuit board 10, e.g. as illustrated in FIG. 21A to FIG. 21H or FIG. 23, or the PCB of FIG. 22A, FIG. 24, FIG. 28 to FIG. 33.

[0195] Current values measured by a current sensor assembly as illustrated in FIG. 1A to FIG. 6, using a semiconductor substrate 831 as illustrated in FIG. 8A or FIG. 8B, and optionally using a package with contact pins but no elongated leads (e.g. as illustrated in FIG. 7) and / or arranged in a "die down current sensor" as described in EP3992653(A1), offer an improved accuracy, inter alia because: they are highly insensitive to a magnetic disturbance field (or strayfield) because the current is derived from a magnetic field difference (or gradient); and they have a good signal-to-noise ratio (SNR) because IMC provides passive signal amplification (also known as "magnetic amplification" or "magnetic gain"); and because the semiconductor surface is oriented perpendicular to the direction of current flow in the interconnection portions, thus the electrical contacts (e.g. leads) are very close to, and / or substantially parallel to the PCB and do not create large loops which are subject to a time-varying flux (thus is highly insensitive to "di / dt disturbances"), and if a "die down current sensor" arrangement is used with a grounded plane under the sensor device, the measurement is also highly insensitive to "dv / dt" disturbances).

[0196] FIG. 9A shows a semiconductor substrate 931 with two magnetic sensor structures SI, S2, spaced apart in the Y-direction by a distance dy. The first magnetic sensor structure SI comprises a vertical Hall element VI having an axis of maximum sensitivity oriented in the X-direction. The second magnetic sensor structure S2 also comprises a vertical Hall element V2 having an axis of maximum sensitivity oriented in the X-direction.

[0197] When this semiconductor substrate 931 is used in a current sensor assembly comprising a conductor 20 with an opening 25 (e.g. as illustrated in FIG. 1A to FIG. IE), and is positioned and oriented relative to the busbar 20 in a similar manner as illustrated in FIG. 2 and FIG. 5, meaning that the sensor structure SI is situated at sensor location A and that the sensor structure S2 is situated at sensor location B, then the following formulas can be used to determine the current:

[0198] Bxl=vl [9]

[0199] Bx2=v2

[0010]

[0200] ABx=(Bxl-Bx2)

[0011] l9a=K9a*ABx

[0012] where Bxl, Bx2 are magnetic field components oriented in the first direction X, and wherein vl, v2 are signals obtained from a first, second vertical Hall element VI, V2, and wherein ABx is a magnetic field difference between these magnetic field components, and K9a is a predefined constant.

[0201] FIG. 9B shows a variant of FIG. 9A, using the same or a similar semiconductor substrate 931 as in FIG. 9A, but rotated by 90° about the Z-axis. When this semiconductor substrate 931 is positioned and oriented relative to a conductor 20 in a manner similar to FIG. 3 and FIG. 6, meaning that the sensor structure SI is situated at sensor location C, and that the sensor structure S2 is situated at sensor location D, the distance between the sensor locations is referred to as dx, and the following formulas can be used to determine the current:

[0202] Byl=vl

[0013]

[0203] By2=v2

[0014]

[0204] ABy=(Byl-By2)

[0015] l9b=K9b*ABy

[0016] where Byl, By2 are magnetic field components oriented in the second direction Y, and wherein vl, v2 are signals obtained from a first, second vertical Hall element Vl, V2, and wherein ABy is a magnetic field difference between these magnetic field components, and K9b is a predefined constant. The predefined constants K9a, K9b can be determined and may be stored in a non-volatile memory, in the same or a similar manner as described above for FIG. 8A and FIG. 8B.

[0205] A current sensor assembly comprising a conductor 20 with an opening 25, and comprising a semiconductor substrate 931 as illustrated in FIG. 9A or FIG. 9B, arranged at least partially inside said opening 25, offers an improved accuracy over known systems, for the same or similar reasons as described above for FIG. 8A and FIG. 8B.

[0206] FIG. 10 shows a semiconductor substrate 1031 with two magnetic sensor structures SI, S2, spaced apart in the Y-direction by a distance dy. This semiconductor substrate 1031 can be seen as a variant of the semiconductor substrate 831 of FIG. 8A where the horizontal Hall elements H2 and H4 are omitted.

[0207] When this semiconductor substrate 1031 is used in a current sensor assembly comprising a conductor 20 with an opening 25 (e.g. as illustrated in FIG. 1A to FIG. IE), and is positioned and oriented as illustrated in FIG. 2 and FIG. 5, the following formulas can be used to determine the current:

[0208] Bxl=hl

[0017]

[0209] Bx2=h3

[0018]

[0210] ABx=(Bxl-Bx2)

[0019] ll0=K10*ABx

[0020] where Bxl, Bx2 are magnetic field components oriented in the first direction X, and wherein hl, h3 are signals obtained from the horizontal Hall elements Hl and H3, and wherein ABx is a magnetic field difference between these magnetic field components, and K10 is a predefined constant.

[0211] In a variant of FIG. 10 (not shown), the semiconductor substrate 1031 is rotated by 90° about the Z-axis, and is used in a current sensor assembly comprising a conductor 20 having an opening 25 (e.g. as illustrated in FIG. lA to FIG. IE), and is positioned and oriented as illustrated in FIG. 3 and FIG. 6, and the following formulas can be used to determine the current:

[0212] Byl=hl

[0017]

[0213] By2=h3

[0018]

[0214] ABy=(Byl-By2)

[0019] ll0b=K10b*ABy

[0020] where Byl, By2 are magnetic field components oriented in the second direction Y, and wherein hl, h3 are signals obtained from the horizontal Hall elements Hl and H3, and wherein ABy is a magnetic field difference between these magnetic field components, and KlOb is a predefined constant.

[0215] The predefined constants K10, KlOb can be determined and may be stored in a non-volatile memory, in the same or a similar manner as described above for FIG. 8A and FIG. 8B. A current sensor assembly comprising a conductor 20 with an opening 25, and comprising a semiconductor substrate 1031 as illustrated in FIG. 10, arranged at least partially inside said opening 25, offers an improved accuracy over known systems, for the same or similar reasons as described above for FIG. 8A and FIG. 8B.

[0216] FIG. 11 shows a semiconductor substrate 1131 with two magnetic sensor structures SI, S2, spaced apart in the Y-direction by a distance dy. This semiconductor substrate 1131 can be seen as another variant of the semiconductor substrate 831 of FIG. 8A wherein the sensor structure SI comprises two integrated magnetic (flux) concentrators IMC1, IMC2 instead of only one, and wherein Hl is arranged near a periphery of IMC1, and H2 is arranged near a periphery of IMC2, and wherein Hl, H2, IMC1 and IMC2 are located on a first virtual line oriented in the first direction X. Likewise, the sensor structure S2 contains two horizontal Hall elements H3, H4 and two integrated magnetic flux concentrators IMC3, IMC4, wherein H3 is located near a periphery of IMC3, and H4 is located near a periphery of IMC4, and wherein H3, H4, IMC3, IMC4 are located on a second virtual line oriented in the X-direction, spaced from the first virtual line by a distance dy.

[0217] When this semiconductor substrate 1131 is used in a current sensor assembly and is positioned and oriented as illustrated in FIG. 2 and FIG. 5, thus sensor structure SI being located at sensor position A, and sensor structure S2 being located at sensor position B, the following formulas can be used to determine the current:

[0218] Bxl=(hl-h2)

[0021]

[0219] Bx2=(h3-h4)

[0022]

[0220] ABx=(Bxl-Bx2)

[0023] lll=Kll*ABx

[0024] where Bxl, Bx2 are magnetic field components oriented in the first direction X, and wherein hl, h2, h3, h4 are signals obtained from the horizontal Hall elements Hl, H2, H3 and H4, and wherein ABx is a magnetic field difference between these magnetic field components, and Kll is a predefined constant.

[0221] In a variant of FIG. 11 (not shown), the semiconductor substrate 1131 is rotated by 90° about the Z-axis, and is used in a current sensor assembly comprising a conductor 20 with an opening 25 (e.g. as illustrated in FIG. 1A to FIG. IE), and is positioned and oriented as illustrated in FIG. 3 and FIG. 6, thus SI being located at position C, and S2 being located at position D, the following formulas can be used to determine the current:

[0222] Byl=(hl-h2)

[0025]

[0223] By2=(h3-h4)

[0026]

[0224] ABy=(Byl-By2)

[0027] lllb=Kllb*ABy

[0028] where Byl, By2 are magnetic field components oriented in the second direction Y, and wherein hl, h2, h3, h4 are signals obtained from the horizontal Hall elements Hl, H2, H3 and H4, and wherein ABy is a magnetic field difference between these magnetic field components, and Kllb is a predefined constant.

[0225] The predefined constants Kll, Kllb can be determined and may be stored in a non-volatile memory, in the same or a similar manner as described above for FIG. 8A and FIG. 8B.

[0226] A current sensor assembly comprising a conductor 20 with an opening 25, and comprising a semiconductor substrate 1131 as illustrated in FIG. 11, arranged at least partially inside said opening 25, offers an improved accuracy over known systems, for the same or similar reasons as described above for FIG. 8A and FIG. 8B.

[0227] In the examples of FIG. 8A to FIG. 11 the semiconductor substrates 831, 931, 1031, 1131 comprise only two magnetic sensor structures SI, S2, which can be situated at sensor positions A and B as illustrated in FIG. 2, or can be situated at sensor positions C and D as illustrated in FIG. 3, and the current is determined as a value proportional to a single magnetic field difference, e.g. proportional to ABx or proportional to ABy, but the present invention is not limited thereto, and will also work if the semiconductor substrate and thus the sensor locations are rotated relative to the conductor 20 over another predefined angle about the Z-axis, for example over 30° or over 45° or over 60°. The components would not be oriented in the X-direction or the Y-direction, but the same formulas mentioned above can be used, but the values of the constants may be different.

[0228] FIG. 12 to FIG. 14 show examples of semiconductor substrates 1231, 1331, 1431, comprising four magnetic sensor structures SI, S2, S3, S4 which can be positioned and oriented such that they are located at the sensor locations A, B, C, D as illustrated in FIG. 4. Such a semiconductor substrate can determine two magnetic field differences ABx and ABy, and may derive two current values from these differences, and / or may detect an error based on a consistency of the two magnetic field differences and / or based on a consistency of the two current values, and / or may determine an overall current value as a function of the two magnetic field differences, e.g. as a linear function of the two magnetic field differences, or as a linear function of the two individual currents, e.g. as a weighted average of the two current values. By combining two magnetic field differences or two current values, the signal-to-noise ratio (SNR) and thus the accuracy may be further improved.

[0229] FIG. 12 shows a semiconductor substrate 1231 comprising four sensor structures SI, S2, S3, S4, each sensor structure comprising an integrated magnetic flux concentrator and two horizontal Hall elements. The semiconductor substrate 1231 can be regarded as a combination of the sensor structures of FIG. 8A and the same sensor structures of FIG. 8A after rotation by 90° about the Z-axis.

[0230] A first current value 112a can be determined using the following formulas: 1

[0231] Bxl=(hl-h2)

[0029]

[0232] Bx2=(h3-h4)

[0030]

[0233] ABx=(Bxl-Bx2)

[0031] ll2a=K12a*ABx

[0032]

[0234] A second current value 112b can be determined using the following formulas:

[0235] Byl=(h5-h6)

[0029]

[0236] By2=(h7-h8)

[0030]

[0237] ABy=(Byl-By2)

[0031] ll2b=K12b*ABy

[0032]

[0238] An error can be detected e.g. by testing a consistency of ABx and ABy, e.g. by testing if a ratio Rl= ABx / ABy lies in a predefined range, and / or by testing if a difference between the current values 112a and 112b is smaller than a predefined threshold, or using another consistency test.

[0239] An overall current value 112 can be determined using for example one of the following formulas: ll2=K12c*ABx + K12d*ABy

[0033]

[0240] I12=wl*ll2a + w2*ll2b

[0034] ll2=(ll2a+ll2b) / 2

[0035] where Bxl, Bx2 are magnetic field components oriented in the first direction X, and ABx is a magnetic field difference between these magnetic field components; and Byl, By2 are magnetic field components oriented in the second direction Y, and ABy is a magnetic field difference between these magnetic field components; and hl to h8 are signals obtained from the horizontal Hall elements Hl to H8, and K12a, K12b, K12c, K12d, wl, w2 are predefined constants.

[0241] These predefined constants can be determined and stored in a non-volatile memory, in the same or a similar manner as described above (FIG. 8A and FIG. 8B).

[0242] A current sensor assembly comprising a conductor 20 with an opening 25, and comprising a semiconductor substrate 1231 as illustrated in FIG. 12, arranged at least partially inside said opening 25, offers an improved accuracy over known systems, for the same or similar reasons as described above for FIG. 8A and FIG. 8B, and furthermore offers error detection capabilities, which may be required for functional safety purposes.

[0243] FIG. 13 shows a semiconductor substrate 1331 comprising four sensor structures SI, S2, S3, S4, each sensor structure comprising two integrated magnetic flux concentrators and two horizontal Hall elements. The semiconductor substrate 1331 can be regarded as a combination of the sensor structures of FIG. 11 and the same sensor structures of FIG. 11 after 90° rotation about the Z-axis. The same formulas

[0029] to

[0035] as mentioned in FIG. 12 are also applicable here, but the values of the predefined constants may be different. The same comments regarding the determination and storage of the predefined constants, and regarding the accuracy and error detection capabilities as mentioned in FIG. 12 are also applicable here.

[0244] FIG. 14 shows a semiconductor substrate 1431 comprising four integrated magnetic flux concentrators IMC1 to IMC4, and eight horizontal Hall elements Hl to H8 arranged near the periphery of one of said IMCs. The four IMC disks are arranged at the corners of a virtual square, and the eight horizontal Hall elements Hl to H8 are located on the edges of that virtual square, for example substantially in the middle of the four edges, as shown.

[0245] The magnetic concentrators IMC1 to IMC4 may have a diameter in the range from 50 to 500 pm.

[0246] The same formulas

[0029] to

[0035] as mentioned in FIG. 12 and FIG. 13 are also applicable here, but the values of the predefined constants may be different.

[0247] The same comments regarding the determination and storage of the predefined constants, and regarding the accuracy and error detection capabilities as mentioned in FIG. 12 and FIG. 13 are also applicable here.

[0248] It is noted that, even though FIG. 8A to FIG. 14 show illustrative examples of semiconductor substrates that comprise the magnetic sensors embedded in a device layer thereof, the present invention is not limited thereto, and it is also possible that the plurality of magnetic sensors are stacked on top of the semiconductor substrate, and preferably electrically connected thereto, e.g. using wire bonding; or that the plurality of magnetic sensors are situated next to the (main) semiconductor substrate, and preferably electrically connected thereto, e.g. using at least one redistribution (RDL) layer, e.g. as used in "wafer level packaging" (WLP) processes.

[0249] FIG. 15A and FIG. 15B show a variant of FIG. 1A and FIG. IB, illustrating that the electrical conductor 20 may have an overall L-shape. As can be appreciated, this does not change the current flow in the two main conductor portions 21, 22 and in the interconnection portions 23, 24.

[0250] FIG. 15A shows the lip or protrusion 11 of the PCB 10 with the sensor device 30 before being inserted into the opening 25 of the conductor 20.

[0251] FIG. 15B shows the lip 11 with the sensor device 30 after insertion.

[0252] FIG. 16A shows an illustrative example of a current sensor arrangement 1600 in front view. The current sensor arrangement comprises: three busbars 20a, 20b, 20c and a single PCB 1610. In a variant, the current sensor arrangement only has two busbars, or more than three busbars.

[0253] Each of the busbars has two main portions and a pair of interconnection portions (e.g. 23a, 24a) spaced apart from each other to form openings 25a, 25b, 25c. The PCB 1610 has a shape with a plurality of cut-outs 44a, 44b, 44c (e.g. three U-shaped cut-outs), and a plurality of lips 11a, lib, 11c (e.g. three rectangular lips 11) extending in a first direction X. Three sensor devices 30a, 30b, 30c are mounted on said lips. The lips 11a, lib, 11c of the PCB 10 with the sensor devices 30a, 30b, 30c mounted thereon, can be at least partially inserted in the respective openings 25a, 25b, 25c of the busbars 20a, 20b, 20c.

[0254] Preferably a small clearance (e.g. at least 0.5 mm, or at least 1.0 mm) is available between the sides of the lips 11 and the sidewalls forming the opening 25, for thermal and / or electrical isolation.

[0255] FIG. 16A shows a front view, and FIG. 16B shows a top view of the busbars 20a, 20b, 20c and of the PCB 10 before insertion. FIG. 16C shows a top view of the current sensor assembly 1600 after the lips 11 are at least partially inserted inside the openings 25. The sensor device 30a is configured for measuring the current lu flowing through the busbar 20a, the sensor device 30b is configured for measuring the current Iv flowing through the busbar 20b, and the sensor device 30c is configured for measuring the current Iw flowing through the busbar 20c.

[0256] In the current sensor assembly 1600, each sensor device may sense interference (cross-talk) from the currents flowing in the other busbars. For example, the sensor device 30a is arranged to measure the current lu flowing through busbar 20a, but may sense a disturbance caused by the current Iv flowing in busbar 20b and the current Iw flowing in busbar 20c. As can be appreciated from FIG. 16B, the magnetic field generated by the current Iv flowing in busbar 20b causes a magnetic field which is mainly oriented in the X-direction at the location of the sensor device 30a. This has no significant impact on the measurement of the By components and thus on ABy because By is perpendicular to the X- direction, but it has an unequal impact on the measurement of Bxl and Bx2 (because the distance between location A and busbar 20b is different from the distance between location B and the busbar 20b). Thus there is some disturbance on ABx measured by sensor 30a due to the currents Iv and Iw. Thus a current measurement based on ABy (e.g. as depicted in FIG. 3) may provide more accurate results than a measurement based on ABx in the current sensor assembly 1600 of FIG. 16C.

[0257] While not absolutely required, it is of course always possible to add a magnetic shielding around each of the interconnection portions, in order to further reduce electromagnetic disturbances or crosstalk. Other techniques to reduce cross-talk known in the art may also be used, such as for example using an inverse cross-talk matrix calculation.

[0258] As can be appreciated from FIG. 16A to FIG. 16C, the lips 11 of the PCB 1610 can be easily inserted into the openings 25 of the electrical conductors during the assembly stage.

[0259] As can be appreciated from FIG. 16C, the solution proposed is highly flexible, in the sense that the PCB can vary between a very compact solution (see also FIG. 21D) and a "single-board solution" (see also FIG. 21A to FIG. 21C), in which the same PCB 1610 further comprises other components or circuits, such as e.g. a controller device 41, etc. FIG. 17A to FIG. 17C show a current sensor assembly 1700 which can be seen as a variant of the current sensor assembly 1600 of FIG. 16A to FIG. 16C. The current sensor assembly 1700 comprises a printed circuit board 1710 having an overall rectangular shape with three U-shaped cut-outs 44a, 44b, 44c. These cut-outs have a shape complementary to the shape of the lips 11a, lib, 11c.

[0260] Referring back to FIG. 17B, each U-shaped cut-out has two leg portions and a bridge portion adjacent three sides of the lips. The lips or protrusions 11a, lib, 11c of the PCB 1710 are situated between respective leg portions of the cut-outs 44a, 44b, 44c. The cut-outs are sufficiently large for allowing the busbars to be inserted in these cut-outs by moving them in the Z-direction relative to the PCB 1710 during assembly of the current sensor assembly.

[0261] FIG. 17B shows an intermediate position of the PCB relative to the busbars which can be obtained by moving the busbars in the Z-direction into the openings 25, or vice versa, by moving the PCB with its openings over the busbars. Or more specifically, in the example shown, the combined shape of the cut-outs and the shape of the lips together form an imaginary rectangle having a width w44 equal to or preferably slightly (e.g. at least 0.5 mm) larger than a width w20 of the conductor, and having a length L44 equal to or preferably slightly (e.g. at least 0.5 mm) larger than the sum of the thickness T20 of the conductor and a length Lil of the lips. Or written mathematically: w44 > w20

[0036]

[0262] L44 > (T20+L11)

[0037]

[0263] It is noted that requirement

[0036] is also applicable for the PCB 1610 of FIG. 16A to FIG. 16C, but the requirement

[0037] is not, because the cut-outs of the PCB 1610 are located at the edge of the PCB.

[0264] FIG. 17C shows the current sensor assembly of FIG. 17B after moving the PCB 1710 in the X- direction, such that the lips 11a, lib, 11c with the sensor devices 30a, 30b, 30c mounted thereon, are at least partially inserted inside the openings 25a, 25b, 25c of the busbars. As mentioned above, the lips may be inserted such that the magnetic sensors or sensor structures of the sensor device 30 are located substantially at the (ideal) locations A and B (as in FIG. 2), or C and D (as in FIG. 3), or A to D (as in FIG. 4), but as also mentioned above, the exact positioning is not critical, because the differential measurement of ABx and ABy has a reduced sensitivity to mounting position offset.

[0265] As can be appreciated from FIG. 16C and FIG. 17C, both the PCB 1610 of FIG. 16C and the PCB 1710 of FIG. 17C may be dimensioned so as to have a relatively large area (e.g. having a size of at least 10 cm x 5 cm) that can be used for mounting other components, such as for example at least a controller device 41 (not shown in FIG. 16C or FIG. 17C but see e.g. FIG. 21A to FIG. 21D).

[0266] FIG. 18A and FIG. 18B show a current sensor assembly 1800 which can be seen as a variant of the current assembly system 1600 illustrated in FIG. 16A to FIG. 16C, after the busbars 20a, 20b, 20c are rotated over 90° about their respective Z-axes. The current sensor assembly 1800 comprises a printed circuit board 1810 that has an overall rectangular shape with three U-shaped cut-outs 44a, 44b, 44c. In the example shown in FIG. 18A and FIG. 18B, the cut-outs are located at an edge of the PCB. The cut-outs have a shape complementary to the shape of the lips 11a, lib, 11c. Each U-shaped cut-out has two leg portions and a bridge portion adjacent three sides of the lips. The lips or protrusions 11a, lib, 11c of the PCB 1810 are situated between respective leg portions of the corresponding cut-outs 44a, 44b, 44c. The lip 11a is situated between the bridge portions of the cut-outs 44a, 44b, and the lip lib is situated between the bridge portions of the cut-outs 44b, 44c. The cut-outs 44a, 44b, 44c are sufficiently large for allowing the busbars 20a, 20b, 20c to be inserted in these cut-outs by moving them in the Z-direction relative to the PCB 1810 during assembly. To this end, the length L44 of the cut-out (measured in the X-direction) is equal to, or preferably slightly larger than the sum of the thickness L20 of the busbar, and the length Lil of the lips. Or stated in mathematical terms:

[0267] L44 > (T20+L11)

[0038]

[0268] The requirement

[0036] is not applicable for the PCB 1810, because the cut-outs of the PCB 1810 are located at the edge of the PCB.

[0269] FIG. 18A shows an intermediate position of the PCB 1810 relative to the busbars 20a, 20b, 20c, before the lips or protrusions 11a, lib, 11c are moved towards the openings 25a, 25b, 25c.

[0270] FIG. 18B shows the busbars and the PCB 1810 of FIG. 18A after moving the PCB 1810 in the X- direction, such that the lips or protrusions 11a, lib, 11c with the sensor devices 30a, 30b, 30c mounted thereon, are at least partially inserted inside the openings 25a, 25b, 25c of the busbars.

[0271] As mentioned above, it is not absolutely required that a geometric center of the sensor structures is located exactly in the middle of the openings, because the measurements are based on magnetic field differences ABx and / or ABy, and these are quite tolerant to a mounting position offset.

[0272] As can be appreciated from FIG. 18B, the PCB 1810 may have a relatively large (e.g. rectangular) area (e.g. having a size of at least 10 cm x 5 cm) that can be used for mounting other components, such as for example at least a controller device 41 (not shown in FIG. 18B, but see e.g. FIG 21E to FIG. 21H).

[0273] In the current sensor assembly 1800, each sensor device (e.g. 30a) may sense interference (cross-talk) from the currents flowing in the other busbars (e.g. 20b and 20c). The magnetic field generated by the current flowing in the interconnection portions 23b, 24b of busbar 20b causes a magnetic field which is mainly oriented in the Y-direction at the locations A, B, C, D of the sensor device 30a. This field has no significant impact on the measurement (at A and B) of the Bx components (because Bx is perpendicular to the Y-direction, and because the distance from A to busbar 20b is equal to the distance from B to busbar 20b) and thus on ABx, but has an unequal impact on the measurement of Byl (at C) and By2 (at D) because the distance between location C and the busbar 20b is different from the distance between location D and the busbar 20b, and thus has some disturbance impact on ABy. Thus a current measurement based on ABx (at A and B, e.g. as described in FIG. 2) may provide more accurate results than a measurement based on ABy (at C and D, e.g. as illustrated in FIG. 3), in the current sensor assembly 1800 of FIG. 18C.

[0274] It is of course always possible to add a magnetic shielding around each of the interconnection portions of the busbars, in order to further reduce electromagnetic disturbances. Other techniques to reduce cross-talk known in the art can also be used, such as for example using inverse cross-talk matrix calculations.

[0275] FIG. 19A and FIG. 19B show a current sensor assembly 1900 which can be considered as a variant of the current sensor assembly 1800 of FIG. 18A and FIG. 18B, wherein the PCB 1910 has an overall rectangular shape with three U-shaped cut-outs 44a, 44b, 44c which are not located at the edge of the PCB 1910. As can be seen, the PCB 1910 may have two relatively large rectangular zones.

[0276] As explained above, the U-shaped cut-outs need to be sufficiently large for allowing insertion of the busbars during assembly. The following requirements are applicable: w44 > w20

[0039]

[0277] L44 > (T20+L11)

[0040]

[0278] Everything else described above is also applicable here, mutatis mutandis.

[0279] FIG. 20 shows a graph with simulation results for the currents flowing in a three-phase current system with three busbars and with a PCB arranged as illustrated in FIG. 16B or FIG. 17B or 18B or FIG. 19B, without a magnetic shield, and without matrix cross-talk correction calculations. The simulation results take into account typical mechanical mounting tolerances.

[0280] FIG. 21A to FIG. 21H show examples of printed circuit boards 2110a to 2110h, comprising a plurality of cut-outs 44, and a plurality of lips or protrusions, 11 and a plurality of magnetic sensor devices 30. In the examples shown, the PCB's have three lips and three sensor devices, but the present invention is not limited thereto, and also work with only two sensor devices or more than three sensor devices.

[0281] The PCB has at least two lips or protrusions 11 accommodating a magnetic sensor device.

[0282] Each sensor device has at least four electrical contacts (e.g. pins or elongated leads) connected to the PCB. Each sensor device is or comprises a semiconductor substrate 31 (not visible in FIG. 21A to FIG. 21H, but see e.g. FIG. ID or FIG. IE or FIG. 5 or FIG. 6) oriented parallel to the PCB. Each semiconductor substrate 31 comprises a plurality of magnetic sensors or magnetic sensor structures for measuring at least two parallel "in-plane" magnetic field components (e.g. Bxl, Bx2 and / or Byl, By2), i.e. magnetic field components oriented parallel to the semiconductor substrate. The PCB has a plurality of cut-outs, e.g. U-shaped cut-outs (see e.g. FIG. 21A, FIG. 21B, FIG. 21E,

[0283] FIG. 21F) or L-shaped cut-outs (see e.g. FIG. 21F, FIG. 21G, FIG. 21H: 44b, 44c), or rectangular cut-outs

[0284] (see e.g. FIG. 21C, FIG. 21D, FIG. 21H: 44a).

[0285] The PCB may optionally further comprise one or more of the following additional components: a controller chip 41, a filter (e.g. a low-pass filter, a band-pass filter), a rectifier, a power switch, a power transistor, a diode, a power diode, a voltage regulator, decoupling capacitors, a dual-H bridge comprising at least two power switches, a connector, etc.

[0286] The PCB 2110a of FIG. 21A is identical or similar to that of FIG. 17B. It has a rectangular circumference, and three U-shaped cut-outs 44a, 44b, 44c.

[0287] The PCB 2110b of FIG. 21B is identical or similar to that of FIG. 16B, and can be seen as a variant of the PCB 2110a of FIG. 21A having a smaller area. The PCB 2110b also has three U-shaped cut-outs 44a, 44b, 44c, but a portion of the cut-outs is located on an edge of the PCB.

[0288] The PCB 2110c of FIG. 21C is a variant of the PCB 2110b of FIG. 21B, but is smaller. The PCB 2110c has three pairs of two rectangular cut-outs oriented parallel to the lips. Each of the lips 11 has a rectangular shape extending in the X-direction, and the PCB has two elongated slots extending in the X- direction, adjacent each of the lips.

[0289] The PCB 2110d of FIG. 21D is a variant of the PCB 2110c of FIG. 21C, but is smaller. The PCB 2110d has two rectangular cut-outs 44a, 44b situated between the lips 11a, lib, 11c.

[0290] The PCB 2110e of FIG. 21E is identical or similar to that of FIG. 19A. This PCB has a rectangular circumference, and three U-shaped cut-outs 44a, 44b, 44c.

[0291] The PCB 2110f of FIG. 21F is identical or similar to the PCB of FIG. 18A and FIG. 18B, and can be seen as a variant of the PCB 2110e of FIG. 21E but having a smaller area. The PCB 2110f also has three U-shaped cut-outs 44a, 44b, 44c, but a portion of the cut-outs is located on an edge of the PCB.

[0292] The PCB 2110g of FIG. 21G is a variant of the PCB 2110f of FIG. 21F, but is smaller. The PCB 2110g has three L-shaped cut-outs.

[0293] The PCB 2110h of FIG. 21H is a variant of the PCB 2110g of FIG. 21G, but is smaller. The PCB 2110H has one rectangular cut-out 44a adjacent lip 11a, and has two L-shaped cut-outs 44b, 44c adjacent lips lib and 11c.

[0294] FIG. 22A and FIG. 22B show an illustrative example of a current sensor assembly 2200 comprising three busbars 20a, 20b, 20c and a single PCB 2210 comprising three sensor devices 30a, 30b, 30c located on three lips 11a, lib, 11c that can be at least partially inserted into openings 25a, 25b, 25c of the busbars. FIG. 22A shows an exploded view. FIG. 22B shows an assembled view.

[0295] The three busbars 20a, 20b, 20c are arranged in parallel, and are conducting three current lu, Iv, Iw flowing mainly in the Y-direction, but the direction of the currents is locally altered to stream into the Z-direction by means of a zig-zag structure formed between two cut-outs 28, 29 starting on opposite sides of the busbar, and having an opening 25a, 25b, 25c in the portion between the cut-outs, e.g. similar as illustrated in FIG. IE.

[0296] The PCB 2210 may contain further components, e.g. a controller device (not shown), one or more power switches, capacitors, diodes, power diodes, power switches, etc.

[0297] FIG. 23 shows a high-level block-diagram of a electrical circuit that may be implemented on printed circuit boards proposed by the present invention, e.g. as illustrated in FIG. 21A to FIG. 21H. This circuit comprises a controller device 41 and at least two or at least three sensor devices 30a, 30b, 30c communicatively connected to the controller device 41.

[0298] Each of the sensor devices comprises at least two magnetic sensors Ml, M2, and a biasing and readout circuit, and an amplifier, and preferably at least one temperature sensor for temperature compensation. The sensor devices 30a, 30b, 30c may optionally further comprise: an analog-to-digital convertor (ADC), a processing circuit, a non-volatile memory, etc. The sensor devices may be configured for providing one or more of the following analog or digital signals to the controller device 41: an analog or digital signal indicative of ABx, an analog or digital signal indicative of ABy, an analog or digital signal indicative of a current derived from ABx, an analog or digital signal indicative of a current derived from ABy, an analog or digital signal indicative of an inconsistency between ABx and ABy (if both are measured), an analog or digital signal indicative of a combination of a current (e.g. 12) derived from ABx and a current (e.g. 13) derived from ABy.

[0299] If the sensor device 30a comprises a digital processor, then it preferably also comprises an analog-to-digital convertor and a non-volatile memory. The latter may contain one or more predefined constants, e.g. conversion factor(s) for converting a difference signal into a current signal, e.g. in accordance with the formulas of FIG. 2 to FIG. 4.

[0300] The controller device 41 may comprise an analog-to-digital convertor, a digital processor, a nonvolatile memory, one or more PWM modules (pulse-width modulation), etc. It is also possible to store the predefined constants in the non-volatile memory of the controller device 41.

[0301] The controller device 41 may have multiple output ports, and may be configured to generate a plurality of control signals to drive one or more on-board or off-board power transistors (not explicitly shown) in known manners.

[0302] FIG. 24 shows another illustrative example of a current sensor assembly 2400 proposed by the present invention. The current sensor assembly 2400 of FIG. 24 can be seen as a variant of the current sensor assembly 1600 of FIG. 16A to FIG. 16C.

[0303] The electrical conductors 20a, 20b, 20c of FIG. 24 each comprise two horizontal portions situated at different height positions (Z direction), interconnected by upright portions (e.g. vertical portions). While not explicitly shown, the electrical conductors of FIG. 16 may also have two horizontal portions, but in FIG. 16 the openings 25 are made in the upright portions of the electrical conductors, whereas in FIG. 24 the openings are not only made in the upright portions, but are partially formed in the upright portions, and partially in the horizontal portions. This offers as an important advantage that the PCB 2410 can be moved into position by a mere vertical movement (indicated by three arrows with "MOV").

[0304] FIG. 25 shows the busbars of FIG. 24 in perspective view. As can be seen in FIG. 25, the electrical conductor 20a has two main body portions 21, 22, and two interconnection portions 23, 24 disposed between the two main body portions. One of the body portions 21 is part of the upright conductor portion, and the other body portion 22 is part of the horizontal conductor portion. The interconnection portions 23, 24 have an overall L-shape and comprise a long leg portion 23v, 24v (oriented vertically) and a short leg portion 23h, 24h (oriented horizontally). The interconnection portions 23, 24 are spaced apart from each other so as to form an opening 25 between them.

[0305] The attentive reader will recognize that the currents flowing through the long leg portions 23v, 24v of FIG. 25 are similar or identical to the currents flowing through the interconnection portions 23,

[0306] 24 of FIG. ID, and that these currents generate magnetic field lines as illustrated in FIG. 2 to FIG. 4. Thus, everything described above is also applicable for the current sensor assembly of FIG. 24, e.g. the current flowing through each busbar can be derived from ABx or ABy or from a combination of both; the same sensor structures shown in FIG. 8A to FIG. 14 can be used, etc.

[0307] Preferably, a distance between the busbars 20a, 20b, 20c measured in the Y-direction, is at least

[0308] 25 mm, or at least 28 mm, or at least 30 mm.

[0309] FIG. 26 shows the busbars of FIG. 24 and FIG. 25 in top view. As can be seen, the opening 25a is not only made in the vertical portion of the busbar, but is also partially made in the horizontal portion of the busbar. Preferably the opening in the horizontal portion extends at least over a distance D25, which is preferably at least equal to, but preferably slightly larger than the thickness T20 of the upright conductor portion. Or written mathematically: D25 > T20. Such a busbar can be made for example by first making the opening (e.g. by piercing or punching), and then bending the busbar.

[0310] A lip 11 is shown between the short leg portions 23h, 24h of the conductor 20c, for illustrative purposes (to illustrate that a PCB with such a lip can be mounted vertically, by a mere movement in the Z-direction). As mentioned above, the width wll of the lips 11 is preferably slightly smaller (e.g. 0.5 mm or 1.0 mm smaller) than the width w25 between the interconnection portions 23, 24.

[0311] FIG. 27 shows the busbars of FIG. 24 to FIG. 26 in side view, showing again that material is removed not only from the upright conductor portion, but also from the horizontal conductor portion, to create an opening 25 or passage with height H25, depth D25, and width W25, such that lips 11 can be moved vertically between the interconnection portions when mounting the PCB relative to the busbars. FIG. 28 shows another illustrative example of a current sensor assembly 2800 proposed by the present invention.

[0312] The current sensor assembly 2800 can be seen as a variant of the current sensor assembly 2400 of FIG. 24. As can be seen, the busbars 20a, 20b, 20c of the current sensor system 2800 also have two horizontal portions and a vertical portion interconnecting the horizontal portions; and the busbars also have a opening which is partially located in the vertical conductor portion and partially located in the horizontal conductor portion, such that a PCB 2810 comprising a plurality of lips 11a, lib, 11c and comprising a plurality of sensor devices 30a, 30b, 30c mounted on said lips, can be mounted relative to the busbars 20a, 20b, 20c in such a way that the sensor devices 30a, 30b, 30c can be positioned at least partially inside said openings 25a, 25b, 25c, moreover by a mere vertical movement of the PCB 2810.

[0313] The horizontal portions and the vertical portion of the busbar may be welded to each other.

[0314] The main difference between the current sensor assembly 2400 of FIG. 24 and the current sensor assembly 2800 of FIG. 28 is that the current measurements of the system 2400 may be somewhat sensitive to cross-talk if the currents are based on the magnetic field difference or gradient dBx / dy, but currents derived from dBy / dx are highly insensitive to cross-talk. In the system 2800 current measurements based on dBx / dy are highly insensitive to cross-talk, but current measurements based on dBy / dx may be somewhat sensitive to cross-talk.

[0315] Thus, the sensor devices of the system 2400 are preferably capable of measuring at least dBy / dx, whereas the sensor devices of the system 2800 are preferably capable of measuring at least dBx / dy. As explained above, if the sensor devices are capable of measuring both dBy / dx and dBx / dy, they also offer error detection capabilities. Furthermore, it is also possible to reduce cross-talk in an active manner, e.g. by matrix multiplications.

[0316] For completeness, it is noted that also the printed circuit boards shown in FIG. 21F, FIG. 21G and FIG. 21H may be used in the assembly of FIG. 28, not only the PCB 2810 shown in FIG. 28.

[0317] And while the openings in the conductors of the current assemblies of FIG. 24 and FIG. 28 allow to insert the PCB by a pure vertical movement, the present invention is of course not limited to assemblies where the PCBs are mounted by a pure vertical movement.

[0318] FIG. 29 shows another illustrative example of a current sensor assembly 2900 proposed by the present invention.

[0319] The current sensor assembly 2900 can be seen as another variant of the current sensor assembly 2400 of FIG. 24. As can be seen, the busbars 20a, 20b, 20c of the current sensor system 2900 also have two horizontal portions and a vertical portion interconnecting the horizontal portions; and the busbars also have a opening which is partially located in the vertical conductor portion and partially located in the horizontal conductor portion, such that a PCB 2910 comprising a plurality of lips 11a, lib, 11c and comprising a plurality of sensor devices 30a, 30b, 30c mounted on said lips, can be mounted relative to the busbars 20a, 20b, 20c in such a way that the sensor devices 30a, 30b, 30c can be positioned at least partially inside said openings 25a, 25b, 25c, moreover by a mere vertical movement of the PCB 2910.

[0320] The horizontal portions and the vertical portion of the busbars 20a, 20c may be welded to each other. The horizontal portions and the vertical portion of the busbar 20b may also be welded to each other, or may be formed by bending.

[0321] The currents flowing through the conductors can be measured using the same principles as explained above.

[0322] It is noted that the three lips 11a, lib, 11c of the PCB 2910 are not oriented in a single direction, but are oriented in three different directions (in the example shown: lip 11a is oriented in the negative Y direction, lip lib is oriented in the negative X-direction, and lip 11c is oriented in the positive Y direction). Also in this embodiment, certain measurements are more sensitive to cross-talk than others, and also in this embodiment, active cross-talk reduction may be applied to further reduce cross-talk.

[0323] FIG. 30 to FIG. 33 show illustrative examples of printed circuit boards that can also be used in the current sensor assembly 2900 of FIG. 29. As can be seen, the PCB 3010 of FIG. 30 and the PCB 3110 of FIG. 31 are relatively large, and each have six rectangular cut-outs 44a to 44f. The PCB 3310 of FIG. 33 is relatively small, and requires only four rectangular cut-outs.

[0324] As described above, the printed circuit boards 2910 of FIG. 29, 3010 of FIG. 30, 3110 of FIG. 31, 3210 of FIG. 32 and 3310 of FIG. 33 comprise a plurality of lips, and comprise a plurality of cut-outs, and comprise a plurality of sensor devices capable of measuring at least two in-plane magnetic field components (Bxl, Bx2 and / or Byl, By2), but may also comprise other chips or components, such as e.g. a controller 41, filters (e.g. Low-Pass or Band-Pass filter), rectifiers, power switches, power transistors, diodes, power diodes, voltage regulators, half-bridge circuit, full-bridge circuit, a fuse, etc.

[0325] The principles of the present invention are explained and illustrated mainly for an assembly comprising a single busbar and a single printed circuit board, and for an assembly comprising three busbars 20 and a single PCB 10 with three lips or protrusions 11, but the present invention is not limited thereto, and also works for an assembly having only two busbars, or four busbars, or more than four busbars.

[0326] References:

[0327] 00 current sensor assembly

[0328] 10 printed circuit board (PCB)

[0329] 11 lip or protrusion Wil width of the lip

[0330] Lil length of the lip

[0331] 20 conductor (busbar)

[0332] W20 width of the main portion of the conductor

[0333] 21, 22 main body portions

[0334] 23, 24 interconnection portions

[0335] 25 opening

[0336] W25 width of the opening

[0337] 26, 27 cross-sections of the interconnection portions

[0338] 28, 29 first, second cut-out in the busbar

[0339] 30 sensor device

[0340] 31 semiconductor substrate

[0341] A, B pair of sensor locations spaced apart in Y-direction

[0342] C, D pair of sensor locations spaced apart in X-direction

[0343] 40 PCB with at least 2 sensors devices

[0344] 41 controller chip

[0345] 44 cut-out in the PCB

[0346] Hl, H2,... first, second, ... Horizontal Hall element hl, h2,... signal obtained from Hl, H2, ...

[0347] VI, V2,... first, second, ... vertical Hall element vl, v2,... signal obtained from VI, V2, ...

[0348] IMC1, IMC2,... first, second, ... integrated magnetic (flux) concentrator

[0349] SI, S2,... first, second, ... magnetic sensor (structure)

Claims

Claims1. A current sensor assembly (1600; 1700; 1800; 1900; 2200; 2400; 2800; 2900) comprising:- a plurality of at least two (electrical conductors (20a, 20b) for conducting at least two or at least three currents, each electrical conductor having two main body portions (21, 22) and two interconnection portions (23, 24) disposed between the two main body portions (21, 22) and extending in parallel with an opening (25) between them;- a printed circuit board (10) extending in a first direction (X) and in a second direction (Y) perpendicular to the first direction, and comprising at least two cut-outs (44a, 44b) and at least two lips or protrusions (11a, lib) accommodating at least two sensor devices (30a, 30b), each sensor device (30) having at least four electrical contacts connected to the printed circuit board (10); each sensor device (30) being or comprising a semiconductor substrate (31) oriented parallel to the printed circuit board (10), and being arranged at least partially inside the opening (25) of a corresponding electrical conductor (20); each sensor device (30a, 30b) comprising a plurality of magnetic sensors for measuring at least two magnetic field components (Bxl, Bx2; Byl, By2) oriented parallel to the semiconductor substrate (10); wherein the two interconnection portions (23, 24) of the electrical conductors (20a, 20b) extend in a third direction (Z) substantially perpendicular to the first and second direction (X, Y).

2. A current sensor assembly (1600; 1700; 1800; 1900; 2200; 2400; 2800; 2900) according to claim1, wherein each lip (11a, lib) has a rectangular shape having a width (wll) smaller than or equal to a distance (w25) between a pair of interconnection portions (23, 24); or wherein each lip (11a, lib) has a trapezoidal shape having a largest width (wll) smaller than or equal to a distance (w25) between a pair of interconnection portions (23, 24); of wherein each lip has a dome shape or a bulb shape or a semi-elliptical shape with a largest dimension measured in the Y-direction which is smaller than or equal to a distance (w25) between a pair of interconnection portions (23, 24).

3. A current sensor assembly (1600; 1700; 1800; 1900; 2200; 2400; 2800; 2900) according to any of the previous claims, wherein each cut-out (44a, 44b) has a predefined shape selected from the group consisting of: a U-shape, an L-shape, or a rectangular shape, a V-shape, an omega-shape, a dome shape, a bulb shape, a semi-elliptical shape.

4. A current sensor assembly (1600; 1700; 1800; 1900; 2200; 2400; 2800; 2900) according to any of the previous claims, wherein the printed circuit board (10) further comprises a controller device (41) electrically connected to each of the at least two sensor devices (30a, 30b); and optionally wherein the printed circuit board (10) further comprises a plurality of power transistors.

5. A current sensor assembly according to any of the previous claims, wherein the plurality of magnetic sensors (30a, 30b) comprise at least two horizontal Hall elements and at least two integrated magnetic concentrators (IMC); and / or wherein the plurality of magnetic sensors comprise at least two vertical Hall elements oriented with their axis of maximum sensitivity in the first direction (X) and spaced apart (dy) in the second direction (Y); and / or wherein the plurality of magnetic sensors comprise at least two vertical Hall elements oriented with their axis of maximum sensitivity in the second direction (Y) and spaced apart (dx) in the first direction (X); and / or wherein the plurality of magnetic sensors comprise at least two magneto-resistive elements oriented with their axis of maximum sensitivity in the first direction (X) and spaced apart (dy) in the second direction (Y); and / or wherein the plurality of magnetic sensors comprise at least two magneto-resistive elements oriented with their axis of maximum sensitivity in the second direction (Y) and spaced apart (dx) in the first direction (X).

6. A current sensor assembly according to any of the previous claims, wherein the plurality of magnetic sensors comprise at least four horizontal Hall elements and at least two integrated magnetic concentrators (IMC); or wherein the plurality of magnetic sensors comprise at least two horizontal Hall elements and at least two integrated magnetic concentrators (IMC); or wherein the plurality of magnetic sensors comprise at least four horizontal Hall elements and at least four integrated magnetic concentrators (IMC); or wherein the plurality of magnetic sensors comprise at least eight horizontal Hall elements and at least four integrated magnetic concentrators (IMC); or wherein the plurality of magnetic sensors comprise at least eight horizontal Hall elements and at least eight integrated magnetic concentrators (IMC).

7. A current sensor assembly according to any of the previous claims,comprising a first conductor (20a) for conducting a first current (lu), and a first sensor device (30a) arranged in an opening (25a) of the first conductor (20a) for measuring said first current (lu); and comprising a second conductor (20b) for conducting a second current (I v), and a second sensor device (30b) arranged in an opening (25b) of the second conductor (20b) for measuring said second current (Iv); and comprising a third conductor (20c) for conducting a third current (Iw), and a third sensor device (30c) arranged in an opening (25c) of the third conductor (20c) for measuring said third current (Iw).

8. A current sensor assembly (1600; 1700; 2400) according to any of the previous claims, wherein the plurality of conductors (20a, 20b) are spaced apart in the second direction (Y); wherein the two interconnection portions (23a, 24a) of each individual conductor (20a) are spaced apart in the second direction (Y); and wherein the lips (11a, lib) of the printed circuit board extend in the first direction (X), and are spaced apart in the second direction (Y).

9. A current sensor assembly (1800; 1900; 2200; 2800) according to any of the claims 1 to 7, wherein the plurality of conductors (20a, 20b) are spaced apart in the first direction (X); wherein the two interconnection portions (23a, 24a) of each individual conductor (20a) are spaced apart in the second direction (Y); and wherein the lips (11a, lib) of the printed circuit board (1810, 1910, 2210) extend in the first direction (X), and are spaced apart apart in the first direction (X).

10. A current sensor assembly according to any of the previous claims, wherein the sensor devices are packaged in a surface mounted package; or wherein the sensor devices are packaged in an SOIC-package, or a QFN package, or a DFN package or a SON Package.

11. A printed circuit board (10) comprising at least two cut-outs (44) and at least two lips or protrusions (11) accommodating at least two sensor devices (30), each sensor device (30) having at least four electrical contacts connected to the printed circuit board; each sensor device being or comprising a semiconductor substrate oriented parallel to the printed circuit board; each sensor device comprising a plurality of magnetic sensors configured for measuring at least two magnetic field components (Bxl, Bx2; Byl, By2) oriented parallel to the semiconductor substrate.

12. A printed circuit board (10) according to claim 11, wherein the lips (11) have a rectangular shape or a trapezoidal shape or a triangular shape or a dome shape or a bulb shape or a semi-elliptical shape; and wherein the cut-outs (44) have a predefined shape selected from the group consisting of: a U-shape, an L-shape, a rectangular shape, a V-shape, an omega-shape, a dome shape, a bulb shape, a semi-elliptical shape.

13. A printed circuit board (10) according to claim 11 or 12, wherein the printed circuit board (10) further comprises a controller device (41) electrically connected to the at least two sensor devices (30a, 30b); and optionally wherein the printed circuit board (10) further comprises at least two power transistors connected to said controller.

14. A printed circuit board (10) according to any of the claims 11 to 13, wherein the sensor devices (30) comprise a plurality of magnetic sensors, and a biasing and readout circuit; and wherein the lips (11) extend in a first direction (X); and wherein each of the sensor devices is configured: i) for measuring two first magnetic field components (Bxl, Bx2) oriented in the first direction (X) at two sensor locations (A, B) spaced apart in a second direction (Y) parallel to the printed circuit board, perpendicular to the first direction (X); and / or ii) for measuring two second magnetic field components (Byl, By2) oriented in the second direction (Y) at two sensor locations (C, D) spaced apart in the first direction (X).

15. A power invertor comprising:- a current sensor assembly according to any of the claims 1 to 10; and / or- a printed circuit board (10) according to any of the claims 11 to 14.

Images