Components and methods for determining stray magnetic field strength

Abstract

The present invention relates to a method for determining an external interfering magnetic field (H) in a magnetic sensor (200) for detecting a rotation angle (ω) of a rotating member (300). D ). The component includes a permanent magnet (310) for generating a magnetic field (H0), which is arranged on a rotating member (300) so that the magnetic poles (312, 314) generate a magnetic field perpendicular to the axis at the magnetic sensor, and the rotating member rotates around the axis. The component also includes a first channel, including a first magnetic sensing element located on the rotation axis and configured to provide first angle data; a second channel, including a second magnetic sensing element (220) located on the rotation axis and configured to provide second angle data, the second magnetic sensing element being spaced apart from the first magnetic sensing element by a predetermined value in the direction of the rotation axis. The component also includes an induction channel, including an electromagnetic coil (260) wound around the rotation axis, the induction channel being suitable for transmitting a current (I coil+ , I coil‑ ).

Description

Technical Field

[0001] The present invention relates to an assembly for determining the strength of a stray magnetic field of an external interfering magnetic field in a magnetic sensor for detecting the rotation angle of a rotating component, and a corresponding method for determining the strength of the stray magnetic field. Background Art

[0002] Typically, magnetoresistive sensors (also referred to herein as magnetic sensors) measure the direction of a magnetic field. Such devices and methods are useful in the field of determining the angle and position of magnetic field sensors, particularly sensors utilizing the magnetoresistive effect.

[0003] The sensor exploits the magnetoresistance effect, which is the tendency of a material (e.g., a ferromagnet) to change its resistance in an externally applied magnetic field. Magnetoresistance is observed in multi-component or multi-layer systems (e.g., magnetic tunnel junctions), giant magnetoresistance (GMR), tunnel magnetoresistance (TMR), colossal magnetoresistance (CMR), and extreme magnetoresistance (EMR), while anisotropic magnetoresistance (AMR) requires only one layer to occur.

[0004] An externally applied magnetic field can be generated by a permanent magnet—an object made of a material that is magnetized to produce its own persistent magnetic field. In the case of a magnetic sensor, to detect the rotational angle of a rotating component, a permanent magnet is attached to the rotating component connected to a rotating shaft, with the sensor element facing the magnet. Because the magnetic field induced by a permanent magnet is time-invariant, the direction of the magnetic field is determined solely by the orientation of the rotating component relative to the sensing element.

[0005] Magnetic sensors offer excellent angular accuracy and high robustness against harsh environmental conditions, playing an important role in various applications, such as manufacturing and transportation. More specifically, magnetoresistive angle sensors are important components due to their low inherent measurement error and high stability. Furthermore, their favorable temperature characteristics and robustness against harsh environmental conditions have led to the relevance of magnetoresistive (MR) sensors in many important applications. For example, in the automotive sector, MR angle sensors are used in electronic power steering, wiper and throttle systems, and engine applications.

[0006] However, interference fields that interfere with the permanent magnetic field can significantly influence the measurement, which may affect the accuracy of the measurement and the safety of the application.

[0007] In particular, future sensors must withstand interference fields of up to 3 kA / m. For automotive applications, magnetoresistive sensors must comply with the ISO 11452-8 specification, which is incorporated by reference into "ISO 11452-8:2015-06 Road vehicles - Component test methods for electrical disturbances from narrowband radiated electromagnetic energy - Part 8: Immunity to magnetic fields." Specifically, this standard requires a sensor robustness of 3 kA / m at test level IV and 0 Hz in Table A.2 of Annex A.2.3 External fields.

[0008] Robustness against interfering fields can be achieved, for example, by shielding against external magnetic fields or by using field gradients for angle measurement. However, such solutions significantly increase system costs. To minimize the effects of stray fields, unacceptably large and robust magnetic disks or block magnets based on expensive materials must be used.

[0009] Alternative solutions can detect and correct interfering fields. However, a need remains for a component that accurately determines the effects of stray magnetic fields in magnetic sensors that detect the rotational angle of rotating components. Advantageously, such a component can be manufactured economically. Furthermore, the component can be designed to be small enough to fit the space requirements of the desired application. Summary of the Invention

[0010] At least one of these objects is solved by the subject matter of the independent claims. Advantageous embodiments of the invention are the subject matter of the dependent claims.

[0011] In particular, the present invention is based on the concept of providing an assembly for determining the strength of stray magnetic field effects in a magnetic sensor that detects the rotational angle of a rotating component. The assembly includes a permanent magnet for generating a magnetic field, which is arranged on the rotating component so as to generate a parallel magnetic field perpendicular to the rotational axis at the sensor location. For example, the magnetic poles extend radially from the rotational axis about which the rotating component rotates. The assembly also includes a first channel, which includes a first magnetic sensing element located on the rotational axis and is configured to provide first angle data. The assembly also includes a second channel, which includes a second magnetic sensing element located on the rotational axis and is configured to provide second angle data, wherein the second magnetic sensing element is spaced apart from the first magnetic sensing element by a predetermined value z in the direction of the rotational axis. The assembly also includes a sensing channel, which includes an electromagnetic coil wound around the rotational axis and is adapted to transmit an electric current. The assembly also includes a processor configured to calculate a first field strength based on a plurality of first angle data received by the first channel and a value of the current passing through the sensing channel. The processor is further configured to calculate a second field strength based on a plurality of second angle data received by the second channel and a value of a current passing through the sensing channel. The processor is further configured to calculate the influence of a stray magnetic field by comparing the first field direction and field strength with the second field direction and field strength. Finally, the first magnetic sensing element and the second magnetic sensing element include three voltage dividers.

[0012] More specifically, the magnetic field generated by the permanent magnet is determined by the distance from the sensing element. Specifically, a first sensor, connected to the processor via a first channel, is configured to determine a first field strength and field direction of the permanent magnetic field at a first distance from the magnet, wherein the first sensor is positioned along the axis of rotation. Additionally, a second sensor, connected to the processor via a second channel and also positioned along the axis of rotation, is configured to determine a second field strength and direction of the permanent magnet at a second distance from the magnet. Thus, both sensors determine angular data representing the same rotational angle of the rotating component.

[0013] Furthermore, the magnetic field generated by the permanent magnet interferes with the excitation field of the coil to determine the field strength in the plane of the first sensor and in the plane of the second sensor. When the planar coil is wound around the axis of rotation, the excitation field is always partially orthogonal to the magnetic field generated by the permanent magnet. This enables a compact design and reduces the computational effort required to determine the field strength of the permanent magnet. Consequently, both sensors determine the magnetic field strength, which differs due to the distance of each sensor from the permanent magnet. In other words, the density of the field vectors of the permanent magnet's magnetic field in the sensor plane of the first sensor differs from the density of the field vectors of the permanent magnet's magnetic field in the sensor plane of the second sensor. Advantageously, each sensor includes an integrated coil to determine the local field strength at each sensor by generating a well-known coil field.

[0014] In other words, each sensor measures the angular position of the permanent magnet relative to its sensor plane twice: once via the first excitation field and once via the second excitation field. The first excitation field is different from the second excitation field. Thus, the processor can determine the field strength generated by the permanent magnet in the plane of the first sensor and in the plane of the second sensor. Advantageously, the first excitation field is equal in magnitude to the second excitation field, but opposite in direction. For example, the current flowing through the sensing channel and the resulting power dissipation are equal for both measurements, but the directions are different.

[0015] In an external magnetic interference field, its interfering influence increases as the field strength at the sensor decreases, and vice versa. This results in different visual angles measured at the two sensors. By measuring the magnetic field strength generated by the permanent magnet at two locations, where the magnetic field density differs, and measuring the field angle at the two locations, the influence of the stray magnetic field generated by the interference source, which interferes with the magnetic field of the permanent magnet, can be calculated, thereby compensating for the effects of the stray field. Advantageously, it is assumed that the distance between the interference source and the component is greater than the size of the component. This assumption is generally particularly correct if the sensor component is compact and the field vectors of the stray magnetic field are homogeneous, i.e., the field vectors of the stray field are parallel and the field vector density is constant at the locations of the two sensors. Based on this assumption, the strength of the interference source can be easily calculated. More specifically, the two sensors measure two different resultant magnetic fields: the field generated by the component (i.e., the field of the permanent magnet and the predefined coil excitation field), and the interfering stray field generated by the interference source. This strength can be calculated based on these assumptions.

[0016] According to one embodiment, the first magnetic sensing element includes three voltage dividers, and the second magnetic sensing element includes three voltage dividers. Each voltage divider forms a half-bridge. The main advantage of three voltage dividers is the optimized arrangement, which reduces the sensor's size in the sensor plane compared to a sensor consisting of an even number of voltage dividers. Furthermore, the three voltage dividers provide a redundant measurement signal.

[0017] In other words, a sensor with three voltage dividers offers similar advantages to a three-wire, three-phase circuit compared to an equivalent two-wire, two-phase circuit at the same line-to-ground voltage. Specifically, a smaller sensor size is required to receive a given amount of signal strength.

[0018] Furthermore, reducing the size of the sensing element in a plane perpendicular to the axis of rotation is advantageous because it relaxes the requirements for the magnetic field generated by the permanent magnet. Specifically, to measure the angle, the magnetic field of the permanent magnet must be uniform within the sensor plane. However, to determine the field strength of the interference source, the magnetic field strength generated by the permanent magnet must diverge (also known as non-uniformity) along the axis of rotation. Therefore, reducing the sensor size in a plane perpendicular to the axis of rotation is advantageous for components that can detect and correct for the field of the interference source. In particular, this also relaxes the volume requirements for the magnet.

[0019] Advantageously, each voltage divider comprises a resistor formed by a magnetoresistive layer arranged in the sensor plane, which exhibits an opposite change in resistance in a magnetic field. This increases the measured amplitude, improving the measurement. This also allows the sensor dimensions in the plane perpendicular to the axis of rotation to be optimized.

[0020] Even more advantageously, each voltage divider includes a first conductive path forming a first resistor and a second conductive path forming a second resistor that provides an inverse resistance change compared to the first conductive path. Thus, the phase angle between the two resistors forming the half-bridge is optimized, thereby increasing signal strength and further reducing the size of the sensor in a plane perpendicular to the axis of rotation. For example, the first conductive path forming the first resistor and the second conductive path forming the second resistor are arranged perpendicularly.

[0021] Furthermore, the three half-bridges allow for a minimal coil design, further minimizing the sensor's dimensions in the sensor plane. In particular, according to an advantageous embodiment, the voltage dividers are evenly distributed, meaning that two adjacent voltage dividers are separated by an angle of 120°, thereby increasing the sensitive sensor area. Additionally or alternatively, the windings of the electromagnetic coils form a triangle. Consequently, the sensor dimensions in a plane perpendicular to the axis of rotation are further reduced.

[0022] According to an advantageous embodiment, the first electromagnetic coil and the first sensing element are fabricated as an integrated circuit on a first die, while the second electromagnetic coil and the second sensing element are fabricated as an integrated circuit on a second die. Fabricating a single coil and a single sensing element on a single die reduces the number of parts. This reduces the number of parts that must be aligned after fabrication, easing alignment tolerances and improving measurement accuracy.

[0023] To increase the range of interference field measurements, the accuracy of magnetic sensors must be improved. Therefore, integrated manufacturing is advantageous for components that can detect and correct for interference field sources. Furthermore, the volume requirements for the magnets can be relaxed.

[0024] Even more advantageously, the second die is stacked on top of the first die encapsulated in an integrated circuit package. Stacking two dies in an integrated package further reduces the parts to be aligned, thereby reducing alignment errors, thereby increasing the range of measuring interference fields and relaxing the volume requirements of the magnet.

[0025] Preferably, the distance z from the integrated circuit of the first sensing element to the integrated circuit of the second sensing element is 0.2 mm to 0.8 mm. Even more preferably, the distance z from the first sensing element to the integrated circuit of the second sensing element is 0.4 mm.

[0026] Furthermore, the top contact surface of the IC package faces the permanent magnet, while the bottom contact surface of the IC package faces the circuit board. This enables a compact design of the IC package and also increases the distance between sensor planes. Consequently, the field emitted by the permanent magnet along the axis of rotation can be optimally used to measure the strength of the stray magnetic field, further easing the need to align components.

[0027] Preferably, the top contact surface has a distance of 0.2 mm to 0.8 mm from the bottom contact surface. Even more preferably, the top contact surface has a distance of 0.4 mm from the bottom contact surface.

[0028] Additionally or alternatively, the first contact means of the integrated circuit package is contacted to the lead frame by a first technique, preferably by wire bonding, and the second contact means of the integrated circuit package is contacted to the lead frame by a second technique, preferably by flip-chip technology. This is a suitable technique for integrating two stacked sensor chips into one package with a defined vertical connection between the sensing structures.

[0029] Advantageously, the integrated circuit package, the circuit board and the processor are covered by a housing, preferably a wall of the housing is arranged on top of the first die, and its thickness is typically 0.05mm to 0.5mm. Thus, the number of parts can be further reduced.

[0030] Additionally or alternatively, the permanent magnet has a short side and a long side, wherein the long side is longer than the short side. Preferably, the long side of the permanent magnet is 2 to 20 times longer than the short side. In other words, it is essential that the magnet is in the form of a rectangular cuboid, such as a bar magnet. This reduces the volume of the magnet used to generate the magnetic field, which has a high divergence along the axis of rotation and is uniform in the sensor plane.

[0031] Even more advantageously, the permanent magnets have their poles formed at opposite ends of the short sides. In other words, the poles of the magnets extend radially from the axis of rotation. The surface of the rectangular cuboid forming the opposing poles is closer to the axis of rotation than the surface of the rectangular cuboid containing the opposing poles.

[0032] Additionally or alternatively, the permanent magnet has a recessed portion on the surface facing the first magnetic sensing element. In other words, the magnet has a U-shaped shape. However, unlike a horseshoe magnet, the opposing poles are also U-shaped. This type of magnet is particularly advantageous for generating a high gradient in the direction extending from the legs of the U-shaped magnet, while also having a nearly uniform magnetic field parallel to the short connecting arm of the U-shaped magnet. As a result, the volume of the magnet can be further reduced, and volume requirements for the magnet can be more easily met.

[0033] Advantageously, the height of the magnet is 1 mm to 5 mm, preferably 3 mm, along the axis of rotation. Additionally or alternatively, the magnet has a width of 1 mm to 5 mm, preferably 3.5 mm, in the direction of magnetization. Additionally or alternatively, the magnet has a length of 5 mm to 10 mm, preferably 7 mm. Additionally or alternatively, the height of the recess is 0.1 mm to 1 mm, preferably 0.5 mm. Additionally or alternatively, the length of the recess is 1 mm to 4.5 mm, preferably 4 mm.

[0034] Additionally or alternatively, the permanent magnet may comprise a rare earth material. This further reduces the volume of the magnet and makes it easier to meet volume requirements. Furthermore, the field strength at the sensor element can be increased, thereby reducing the influence of external interference fields on the angle measurement.

[0035] The present invention also relates to a method for sensing the strength of a stray magnetic field in a magnetic sensor that detects the rotation angle of a rotating member using an assembly according to the above assembly. The method comprises the following steps:

[0036] Based on the plurality of first angle data received by the first channel and the value I of the current passing through the sensing channel coil+ , I coil- , the processor calculates the first field strength H t ;

[0037] Based on the multiple second angle data received by the second channel and the value I of the current passing through the sensing channel coil+ , I coil- , the processor calculates the second field strength H b ;

[0038] Calculating, by the processor, the stray magnetic field H by comparing the first magnetic field strength with the second magnetic field strength and the first measured magnetic field angle with the second measured magnetic field angle s interference effects.

[0039] Advantageously, the first field strength is calculated by passing two different current values through the sensing channel and receiving different sensor output voltages for the two different current values; the second field strength is calculated by passing two different current values through the sensing channel and receiving different sensor output voltages for the two different current values.

[0040] The accompanying drawings are incorporated into and form a part of the specification to illustrate several embodiments of the present invention. Together with the description, these drawings serve to explain the principles of the present invention. The drawings are only for the purpose of illustrating preferred and alternative examples of how to make and use the present invention and are not to be construed as limiting the present invention to the embodiments shown and described.

[0041] Furthermore, several aspects of the embodiments may form the solution according to the invention alone or in different combinations. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Further features and advantages will become apparent from the following more particular description of various embodiments of the invention, as illustrated in the accompanying drawings, in which like reference numerals refer to like elements, and in which:

[0043] Figure 1 Schematic diagram of components for determining and compensating for the effects of stray magnetic fields in a magnetic sensor that detects the rotation angle of a rotating component.

[0044] Figure 2 is the vector diagram of the magnetic field.

[0045] Figure 3 is a schematic diagram of an integrated circuit including an AMR sensing element and a coil.

[0046] Figure 4 yes Figure 3 Detailed view of the coil of an integrated circuit.

[0047] Figure 5 yes Figure 3 Detailed view of the sensing element of the integrated circuit.

[0048] Figure 6 yes Figure 3 Schematic circuit diagram of an integrated circuit.

[0049] Figure 7 is a vector diagram of the magnetic field generated by the permanent magnet and the excitation field generated by the coil.

[0050] Figure 8 yes Figure 7 Another view of the vector diagram of the magnetic field.

[0051] Figure 9 is a schematic diagram of an integrated circuit package according to a first embodiment.

[0052] Figure 10 is a schematic diagram of an integrated circuit package according to a second embodiment.

[0053] Figure 11 is a schematic side view of the permanent magnet and integrated circuit package. and

[0054] Figure 12 yes Figure 11 Bottom view of . DETAILED DESCRIPTION

[0055] The present invention will now be explained in more detail with reference to the accompanying drawings. Figure 1 , shows a schematic diagram of an assembly 100 for determining the strength of a stray magnetic field in a magnetic sensor 200 that detects a rotation angle of a rotating member 300 .

[0056] The magnetic sensor 200 includes a first magnetic sensing element 210 and a second magnetic sensing element 220. The first magnetic sensing element 210 and the second magnetic sensing element 220 are connected to a circuit board 230, such as a printed circuit board.

[0057] Rotating member 300 includes permanent magnet 310 attached to rotating shaft 320. Rotating member rotates about a rotation axis indicated by arrow 330. The permanent magnet is magnetized in a direction extending from the rotation axis, thereby forming a south magnetic pole 312 and a north magnetic pole 314.

[0058] First sensing element 210, second sensing element 220, and a permanent magnet are arranged on the rotation axis. First sensing element 210 and second sensing element 220 extend in a plane perpendicular to the rotation axis. First sensing element 210 and second sensing element 220 are spaced a predetermined distance from magnet 310, and first sensing element 210 and second sensing element 220 are spaced a predetermined distance apart.

[0059] The generated magnetic field H0 is indicated by graph 400. The magnetic field magnitude |H0| of the permanent magnet decreases in a direction toward the first sensing element 210 and the second sensing element 220.

[0060] Now refer to Figure 2 , which shows a vector diagram of the magnetic field, showing the interfering stray magnetic field H D The vector H0 represents the magnetic field of the permanent magnet in the plane of the first sensing element. The vector f·H0 represents the magnetic field of the permanent magnet in the plane of the second sensing element. The interference field is represented by the vector H DSpecifically, this diagram assumes that the distance between the component and the interference field source is greater than the component's dimensions, specifically the distance between the permanent magnet and the second sensing element. Therefore, it can be assumed that the direction and intensity of the interference source are uniform across the component. This assumption generally holds true. However, if it does not, the intensity of the interference field can be determined using more advanced calculations.

[0061] By using the second sensing element to measure the interference field f·H0+H D The intensity of the interference field H0+H is measured using the first sensing element D , the strength of the influence of the interference field of the interference source can be calculated and compensated for the angle measurement.

[0062] Now refer to Figure 3 , shows a schematic diagram of an integrated circuit 240 including an AMR sensing element 250 and a coil 260. The sensing element 250 is arranged in one layer of the integrated circuit, and the coil 260 is arranged in another adjacent layer. According to one embodiment, each of the first sensing element 210 and the second sensing element 220 is composed of Figure 3 The integrated circuit shown is formed, thereby forming a first die and a second die.

[0063] Coil 260 according to an advantageous embodiment will now be described in detail. In particular, Figure 4 Shown include Figure 3 A detailed view of a layer of coil 260 of an integrated circuit. Coil 260 has multiple windings arranged around an axis of rotation. Coil 260 contacts the center of the integrated circuit via a first contact point. The coil's windings are arranged spirally around the contact point, with each winding generally following a triangular shape. The coil's windings are arranged in a layer of the integrated circuit. In the illustrated coil embodiment, the corners of each triangle forming the windings are rounded, minimizing the space required for the coil.

[0064] In addition, reference Figure 5 , showing Figure 3 2 shows the arrangement of sensing elements of an integrated circuit. The sensing elements include three voltage dividers 252, 254, and 256. The three voltage dividers 252, 254, and 256 are arranged in the plane of the integrated circuit. The voltage dividers 252, 254, and 256 are symmetrically distributed within a layer of the integrated circuit. The angle between two adjacent voltage dividers is 120°.

[0065] The three voltage dividers 252, 254, 256 are similarly formed. An exemplary voltage divider 252 is described in detail. The voltage divider 252 comprises a first resistor 251 and a second resistor 253. The first ends of the resistors 251, 253 are interconnected, and the second ends of the resistors 251, 253 are connected to contact pads that enable electrical connection to a supply voltage and a signal evaluation unit.

[0066] The magnetoresistive strips arranged in this layer form resistors 251, 253. The magnetoresistive strips are connected to form a conductive path. Thus, the magnetic field direction of the permanent magnet can be measured.

[0067] Specifically, each path curves from the center of the integrated circuit to the outer portion of the integrated circuit. The path consists of a longer parallel portion and a shorter portion, with the shorter portion being shorter than the longer portion. The shorter portion extends generally in a direction from the center of the integrated circuit to the outer portion of the integrated circuit. The parallel portion of the first resistor 251 is arranged perpendicular to the parallel portion of the second resistor 253. The resistors forming a voltage divider in a substantially perpendicular arrangement can measure the direction of a magnetic field because they interact with opposite phases to alter the magnetic field, thereby generating a measurement signal.

[0068] like Figure 3 As shown, the arrangement of the coil 260 forming the sensing element 250 and the arrangement of the three voltage dividers are optimized to minimize the space requirements of the integrated circuit.

[0069] In addition, reference Figure 6 , showing Figure 3 Schematic circuit diagram of an integrated circuit. The induction channel includes a coil 260 connected to a first contact node 262 and a second contact node 264. The direction of the magnetic field can be influenced by the direction of the current applied to the induction channel. In particular, the current can be I coil+ or the opposite direction of I coil- .

[0070] like Figure 6 As further shown, the measurement channel includes three voltage dividers. Each voltage divider includes a first terminal connected to ground and a first terminal connected to U b1 、U b2 or U b3 The second end and the center tap. Figure 5 As explained, the angle between two adjacent voltage dividers is 120°. The center taps of the two adjacent voltage dividers are interconnected, and each voltage divider forms a half bridge, thereby forming a bridge with an output voltage U a1 、U a2 and U a3 Therefore, based on the output voltage, the angle of rotation can be determined.

[0071] also, Figure 7 The overall vector diagram of the magnetic field generated by the permanent magnet and the excitation field generated by the coil 260 is shown. The angular position ω is given by the components x and y of the magnetic field H0 in the sensing plane. coil The coil 260 induces an additional field in the sensing plane, and the measured angle changes.coil is orthogonal to H0, so the resultant field strength of the permanent magnet in the sensing plane can be calculated.

[0072] Figure 8 FIG. 1 shows a vector diagram of the magnetic field measured by the sensing element according to an advantageous embodiment. Current flows through the sensing channel in the opposite direction, i.e., through the current I coil+ and I coil- , so the induced electric field is +H coil And once for -H coil As a result, the influence of the coil on the induced magnetic field is maximized and the measurement for determining the field strength of the permanent magnet is optimized.

[0073] Figure 9 A schematic diagram of an integrated circuit package 500 in accordance with an advantageous embodiment is shown. Integrated circuit package 500 includes a circuit board 230, such as a lead frame 230, a first die having a first sensing element 210, and a second die having a second sensing element 220. Integrated circuit package 500 is covered by a housing 510.

[0074] like Figure 9 As further shown, the bottom contact surface 222 of the integrated circuit package faces the lead frame 230. The top contact surface 212 of the integrated circuit package faces the permanent magnet, which is Figure 9 Not shown.

[0075] The top contact surface 212 includes a first contact device 214, while the bottom contact surface 222 includes a second contact device 224. The first contact device 214 is contacted to the lead frame 230 by a first contact technology, preferably by wire bonding using a gold wire 216. The second contact device 224 is contacted to the lead frame 230 by a second contact technology, preferably by flip chip bonding using a solder 226 containing Sn, for example. Such an arrangement is particularly advantageous for a compact design of the integrated circuit package by maximizing the distance between the sensing planes included in the contact surfaces 212 and 222.

[0076] Figure 10 A schematic diagram of an integrated circuit package 500 according to an alternative embodiment is shown. The integrated circuit package 500 includes a lead frame 230, a first die having a first sensing element 210, and a second die having a second sensing element 220. The integrated circuit package 500 is covered by a housing 510.

[0077] Advantageously, the integrated circuit package 500 also houses a processor that is not in the Figure 9 and Figure 10As described above, the processor calculates the stray magnetic field by comparing the first field strength calculated based on the data measured by the first sensing element with the second field strength calculated based on the data measured by the second sensing element.

[0078] Figure 11 A schematic side view of a permanent magnet 310 and a sensing element (eg, an integrated circuit package 500 , partially forming an assembly) is shown. Figure 12 yes Figure 11 Bottom view of .

[0079] According to this embodiment, permanent magnet 310 has a U-shape. The open portion of U-shaped magnet 310 faces integrated circuit package 500. The arms of U-shaped permanent magnet 310 extend in direction z, i.e., toward integrated circuit package 500. The elements interconnecting the arms extend in direction y, i.e., parallel to integrated circuit package 500. South magnetic pole 312 and the opposing north magnetic pole 314 are formed by surfaces extending in direction zy. According to this embodiment, axis z is the axis of rotation.

[0080] Figure 12 The arrows plotted in FIG. 5 represent the vectors of the magnetic field generated by permanent magnet 310 in the plane of integrated circuit package 500. In particular, U-shaped permanent magnet 310 with poles 312 and 340 is optimized so that the field vectors of the magnetic field components in the sensor plane can be assumed to be parallel within the dimensions of integrated circuit package 500.

[0081] Although the above aspects of the components have been described separately, each combination can produce a synergistic effect. In particular, each combination of small size sensors (e.g., by reference to Figures 3 to 5 Disclosed advantageous embodiments), optimized packaging (e.g., with reference to Figure 9 and Figure 10 The advantageous embodiment shown is disclosed), and optimized magnets (e.g., by Figure 11 and Figure 10 In particular, the synergy is that a small-volume magnet can be used to generate a parallel magnetic field perpendicular to the rotation axis in the sensor plane, which has a high divergence in the direction of the rotation axis across the entire assembly.

[0082] For a magnetic field with H0 = 25 kA / m and H coilAn exemplary calculation of an embodiment with a magnetic field of 1 kA / m demonstrates that the output voltage varies with a 360° period depending on the field angle ω (°). Therefore, even when constructed using AMR technology with a 180° period, such a component is capable of detecting the field angle over the entire 360° range. Another important characteristic of such AMR technology systems is that there is no angle at which multiple signals show no coil field dependency. Therefore, the three signal variation values contain sufficient information at each angular position to detect the field angle, specifically the decision values in the ranges 0-180 and 180-360°, as well as the total amplitude of these signal variation curves. The total amplitude of the signal variation curves, together with the actual signal amplitude itself and the known coil field, allows calculation of the magnetic field strength at the sensor location. The output signal is averaged over both coil current directions. This allows highly accurate angular detection of the field at the sensor location.

[0083] According to another embodiment not shown in the figures, a magnetoresistive layer arranged in the sensor plane and having different resistance changes in a magnetic field can be realized by an angle between the resistors being greater than 0° and less than 180°.

[0084] Reference numerals

[0085] 100 components

[0086] 200 Magnetic Sensor

[0087] 210 first magnetic sensing element

[0088] 212 top contact surface

[0089] 214 First contact device

[0090] 216 Wire Bonding

[0091] 220 second magnetic sensing element

[0092] 222 bottom contact surface

[0093] 224 Second contact device

[0094] 226 Connection between sensor pad and lead frame

[0095] 230 circuit board

[0096] 240 integrated circuits

[0097] 250 sensing elements

[0098] 251, 253 resistors

[0099] 252, 254, 256 voltage dividers

[0100] 260 Coil

[0101] 262, 264 contact nodes

[0102] 300 rotating components

[0103] 310 permanent magnet

[0104] 312 South Magnetic Pole

[0105] 314 North Magnetic Pole

[0106] 320 Rotation Axis

[0107] 330 Arrow indicating the axis of rotation

[0108] 400 Graph indicating magnetic field H0

[0109] 500 integrated circuit packaging

[0110] 510 Insulation mold material

Claims

1. A component (100) for determining the influence of an external interfering magnetic field (HD) in a magnetic sensor (200) for detecting a rotation angle (ω) of a rotating member (300), the component (100) comprising: a permanent magnet (310) for generating a magnetic field (H0), the permanent magnet (310) being arranged on the rotating member (300) so that magnetic poles (312, 314) generate a magnetic field perpendicular to an axis at the magnetic sensor, and the rotating member (300) rotates around the axis; A first channel including a first magnetic sensing element (210) located on the rotation axis, the first channel being configured to provide first angle data representing an angle of a magnetic field; a second channel comprising a second magnetic sensing element (220) centered on the rotation axis, the second channel being configured to provide second angle data representing an angle of the magnetic field, wherein the second magnetic sensing element (220) is spaced apart from the first magnetic sensing element (210) by a predetermined value z in the direction of the rotation axis; The induction channel comprises an electromagnetic coil (260) wound around a rotation axis, wherein the induction channel is suitable for transmitting an electric current (I coil+ , I coil- ), the electromagnetic coil (260) is used to generate a magnetic field (H) induced in the plane of the first magnetic sensing element (210) and the plane of the second magnetic sensing element (220) coil ), where the magnetic field (H coil ) is partially orthogonal to the magnetic field generated by the permanent magnet in the plane of the first magnetic sensing element and the plane of the second magnetic sensing element; The processor is configured to: The first field strength is calculated based on a plurality of first angle data received by the first channel, wherein the plurality of first angle data is a first value (I coil+ ) detected and used to flow through the sensing channel to generate a second excitation field (I coil- ), the first excitation field is different from the second excitation field, The second field strength is calculated based on a plurality of second angle data received by the second channel, wherein the plurality of second angle data is a first value (I coil+ ) detected and used to flow through the sensing channel to generate a second value of the current (I coil- ), the fourth excitation field is different from the third excitation field, calculating a stray magnetic field component orthogonal to the magnetic field (H0) by comparing the first field strength and the second field strength; Each of the first magnetic sensing element (210) and the second magnetic sensing element (220) includes three voltage dividers (252, 254, 256).

2. The assembly (100) according to claim 1, wherein Each voltage divider (252, 254, 256) comprises a resistor (251, 253) formed by magnetoresistive layers arranged in the sensor plane, the magnetoresistive layers having opposite resistance changes in a magnetic field.

3. The assembly according to claim 2, wherein Each voltage divider (252, 254, 256) comprises a first conductive path forming a first resistor (251) and a second conductive path perpendicular to the first conductive path and forming a second resistor (253).

4. The assembly (100) according to claim 1, wherein The windings of the electromagnetic coil (260) form a triangle.

5. The assembly (100) according to claim 1, wherein The first electromagnetic coil and the first magnetic sensing element (210) are manufactured as an integrated circuit forming a first die, and wherein the second electromagnetic coil and the second magnetic sensing element (220) are manufactured as an integrated circuit forming a second die.

6. The assembly (100) according to claim 5, wherein The second die is stacked on top of the first die and packaged together in an integrated circuit package (500).

7. The assembly (100) according to claim 6, wherein A top contact surface (212) of the integrated circuit package (500) faces the permanent magnet (310), and wherein a bottom contact surface (222) of the integrated circuit package (500) faces the circuit board.

8. The assembly (100) according to claim 7, wherein A first contact device (214) of a first magnetic sensing element in the integrated circuit package (500) is contacted to a lead frame by a first technique, and a second contact device (224) of a second magnetic sensing element in the integrated circuit package (500) is contacted to the lead frame by a second technique.

9. The assembly (100) according to claim 8, wherein The integrated circuit package (500), the lead frame and the processor are covered by a common housing (510).

10. The assembly (100) of claim 1, wherein The permanent magnet (310) has a short side and a long side, wherein the long side is longer than the short side.

11. The assembly (100) according to claim 10, wherein Magnetic poles (312, 314) of permanent magnets comprising rare earth material are formed at opposite ends of the short sides.

12. The assembly (100) according to claim 10, wherein The permanent magnet (310) has a recessed portion on a surface facing the first magnetic sensing element, and / or The permanent magnet has a north pole and a south pole, and the north pole and the south pole are located on both sides of the rotation axis on a side of the magnet facing the sensor.

13. The assembly (100) of claim 8, wherein: The first technology is a wire bonding technology, and the second technology is a flip chip technology.

14. The assembly (100) of claim 10, wherein: The long side of the permanent magnet (310) is 2 to 20 times longer than the short side.

15. A method for sensing stray magnetic fields in a magnetic sensor (H s ) method, wherein the magnetic sensor detects the rotation angle of the rotating member using the assembly according to any one of claims 1 to 14, Based on a plurality of first angle data representing magnetic field angles received by the first channel, a first field strength is calculated by a processor, wherein, The plurality of first angle data are first values (I coil+ ) detected and used to flow through the sensing channel to generate a second excitation field (I coil- ), the first excitation field is different from the second excitation field, The processor calculates the second field strength based on a plurality of second angle data representing the magnetic field angle received by the second channel, wherein the plurality of second angle data is a first value (I coil+ ) detected and used to flow through the sensing channel to generate a second value of the current (I coil- ), the fourth excitation field is different from the third excitation field, By comparing the first field strength and the second field strength, the stray magnetic field (H s ).

16. The method according to claim 15, wherein Based on the angle information and the information about the field strength of the field at the two sensors, an undisturbed angle value is calculated, wherein the undisturbed angle value is equal to the magnetic field angle which is not disturbed by the external interference field.

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