Magnetic field sensor with optimized coil configuration for flux guide reset

Abstract

A sensor structure comprising a sense element, a flux guide, and a flux guide reset mechanism. The flux guide is configured to guide magnetic flux within a plane for detection by the sense element. The flux guide reset mechanism is configured to set the flux guide to a predetermined magnetic orientation. The flux guide reset mechanism comprises at least a first coil and a second coil. The first coil is configured to generate a first magnetic field. The first coil comprises a first coil segment. The second coil is configured to generate a second magnetic field. The second coil comprises a second coil segment. The flux guide is disposed between the first coil and the second coil. The first coil segment and the second coil segment are configured such that a first magnetic field profile of the first magnetic field and a second magnetic field profile of the second magnetic field are coherent with respect to at least a region of the flux guide that overlaps with the sense element.

Description

Technical Field

[0001] This disclosure relates generally to sensors, and more specifically to magnetic field sensors. Background Technology

[0002] The sensor device may include a magnetoresistive sensor configured to detect an in-plane magnetic field. Additionally, the sensor device may include a flux guide for directing an external field (such as a z-axis field) into the xy plane for sensing by the in-plane magnetoresistive sensor. The flux guide has a preferred uniform magnetization orientation for optimal z-axis response. This preferred magnetization orientation can be disturbed, for example, by exposure to a very large external magnetic field, which may introduce domains separated by domain walls into the flux guide. This can result in a lower signal-to-noise ratio (SNR) and drift in the magnetoresistive sensor offset readings. The uniform magnetization orientation of the flux guide can be reset by a reset operation. However, such a reset operation typically relies on a large operating current, thus relying on relatively large voltage overhead and / or significant power consumption. These relatively large operating requirements tend to make sensor devices with flux guide reset mechanisms unsuitable for mobile and smartphone applications. Summary of the Invention

[0003] The following is an overview of certain embodiments described in detail below. The described aspects are presented merely to provide the reader with a brief overview of these particular embodiments, and the description of these aspects is not intended to limit the scope of this disclosure. In fact, this disclosure may cover various aspects that may not be explicitly set forth below.

[0004] According to at least one aspect, a sensor structure includes a sensing element, a flux guide, and a flux guide reset mechanism. The flux guide is configured to guide magnetic flux in at least a plane for detection by the sensing element. The flux guide reset mechanism is configured to set the flux guide to a predetermined magnetic orientation. The flux guide reset mechanism includes a first coil and a second coil. The first coil is configured to generate a first magnetic field. The second coil is configured to generate a second magnetic field. The flux guide is disposed between the first coil and the second coil. The first coil segment and the second coil segment are arranged relative to each other such that a first magnetic field distribution of the first magnetic field and a second magnetic field distribution of the second magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

[0005] According to at least one aspect, a sensor structure includes a sensing element, a flux guide, and a flux guide reset mechanism. The flux guide is configured to guide magnetic flux in at least a plane for detection by the sensing element. The flux guide reset mechanism is configured to set the flux guide to a predetermined magnetic orientation. The flux guide reset mechanism includes at least a first coil and a second coil. The first coil is configured to generate a first magnetic field. The first coil includes a first coil segment overlapping the flux guide. A second coil is configured to generate a second magnetic field. The second coil includes a second coil segment overlapping the flux guide. A third coil is configured to generate a third magnetic field. The third coil includes a third coil segment overlapping the flux guide. The flux guide has a side facing the first coil and another side facing the second and third coils. The flux guide reset mechanism is configured such that the number of second coil segments overlapping the flux guide is less than the number of third coil segments overlapping the flux guide.

[0006] According to at least one aspect, a sensor structure includes a sensing element, a flux guide, and a flux guide reset mechanism. The flux guide is configured to guide magnetic flux in at least a plane for detection by the sensing element. The flux guide reset mechanism is configured to set the flux guide to a predetermined magnetic orientation. The flux guide reset mechanism includes a first coil and a second coil. The first coil is configured to generate a first magnetic field. The first coil includes a first coil segment overlapping the flux guide. The second coil is configured to generate a second magnetic field. The second coil includes a second coil segment overlapping the flux guide. The third coil is configured to generate a third magnetic field. The third coil includes a third coil segment overlapping the flux guide. The flux guide has a side facing the first coil and another side facing the second and third coils. The first and third coil segments are configured such that a first magnetic field distribution of the first magnetic field and a third magnetic field distribution of the third magnetic field are coherent relative to at least a portion of the flux guide overlapping the sensing element.

[0007] These and other features, aspects and advantages of the invention will be discussed in the following detailed description with reference to the accompanying drawings, in which the same characters denote similar or identical parts. Attached Figure Description

[0008] Figure 1 This is a diagram of an example magnetic field sensor that includes three differential sensors, each of which is formed by sensing elements connected in a Wheatstone bridge configuration.

[0009] Figure 2A This is a top view of a magnetic field sensor according to an exemplary embodiment of the present disclosure, the magnetic field sensor having an arrangement of sub-blocks forming a Z sensor, wherein each sub-block includes a reset mechanism.

[0010] Figure 2B yes Figure 2A A top view of a sub-block showing a first coil associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0011] Figure 2C yes Figure 2A A top view of a sub-block showing a second and third coil associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0012] Figure 3 This is a cross-sectional view of a portion of a sensor structure according to an exemplary embodiment of the present disclosure.

[0013] Figure 4A This is a conceptual cross-sectional view of a first example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0014] Figure 4B This illustrates the in-plane component of the magnetic field density relative to the plane along an exemplary embodiment of this disclosure. Figure 4A The graph shows the distance of the flow guide in the flow guide reset mechanism.

[0015] Figure 4C This illustrates an example embodiment according to the present disclosure. Figure 4A The graph shows the total magnetic field density of the flux guide reset mechanism relative to the in-plane component along the distance of the flux guide.

[0016] Figure 5A This is a conceptual cross-sectional view of a second example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0017] Figure 5B The illustrations are exemplary embodiments according to this disclosure. Figure 5A The graph shows the in-plane component of the magnetic field density of the flux guide reset mechanism relative to the distance along the flux guide.

[0018] Figure 5C The illustrations are exemplary embodiments according to this disclosure. Figure 5A The graph shows the total magnetic field density of the flux guide reset mechanism relative to the in-plane component along the distance of the flux guide.

[0019] Figure 6A This is a conceptual cross-sectional view of a third example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0020] Figure 6B The illustration shows the magnetic field density relative to the direction of the magnetic field along an exemplary embodiment of the present disclosure. Figure 6AThe graph shows the in-plane component of the distance of the flux guide in the flux guide reset mechanism.

[0021] Figure 6C This illustrates an example embodiment according to the present disclosure. Figure 6A The graph shows the total magnetic field density of the flux guide reset mechanism relative to the in-plane component along the distance of the flux guide.

[0022] Figure 7A This is a conceptual cross-sectional view of a fourth example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0023] Figure 7B This illustrates an example embodiment according to the present disclosure. Figure 7A The graph shows the in-plane component of the magnetic field density of the flux guide reset mechanism relative to the distance along the flux guide.

[0024] Figure 7C This illustrates an example embodiment according to the present disclosure. Figure 7A The graph shows the total magnetic field density of the flux guide reset mechanism relative to the in-plane component along the distance of the flux guide.

[0025] Figure 8A This is a conceptual cross-sectional view of a fifth example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure.

[0026] Figure 8B This illustrates an example embodiment according to the present disclosure. Figure 8A The graph shows the total magnetic field density of the flux guide reset mechanism relative to the in-plane component along the distance of the flux guide.

[0027] Figure 9 This is a conceptual cross-sectional view of a sixth example of a flux guide reset mechanism associated with a sensing element and a flux guide according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0028] The embodiments described herein have been shown and described by way of example, and their many advantages will be understood from the foregoing description. It will be apparent that various changes in the form, construction, and arrangement of the components may be made without departing from the disclosed subject matter or sacrificing one or more of its advantages. In fact, the descriptive form of these embodiments is merely illustrative. These embodiments are readily adaptable to various modifications and alternatives, and the following claims are intended to encompass and include these variations, and are not limited to the specific forms disclosed, but rather cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

[0029] Figure 1 A schematic diagram of an example magnetoresistive (MR) sensor 100 is shown. This MR sensor includes a first differential sensor 102, a second differential sensor 122, and a third differential sensor 142 for detecting the component directions of a field applied along a first axis 120 (e.g., the y-axis direction), a second axis 140 (e.g., the x-axis direction), and a third axis 160 (e.g., the z-axis direction), respectively. Each of the first differential sensor 102, the second differential sensor 122, and the third differential sensor 142 is formed by unshielded sensing elements connected in a Wheatstone bridge configuration. Thus, the first differential sensor 102 is formed by the connection of multiple sensing elements 104, 106, 108, 110 in a bridge configuration on corresponding pinned layers 112, 114, 116, 118, wherein each pinned layer 112-118 is magnetized in the x-axis direction. In a similar manner, the second differential sensor 122 is formed by the connection of a plurality of sensing elements 124, 126, 128, 130 in a bridge configuration on corresponding plurality of pinned layers 132, 134, 136, 138, each pinned layer 132, 134, 136, 138 being magnetized in the y-axis direction perpendicular to the magnetization direction of pinned layers 112, 114, 116, 118.

[0030] Furthermore, the third differential sensor 142 is in the same plane as the first sensor 102 and the second sensor 122. The third differential sensor 142 is formed by connecting multiple sensing elements 144, 146, 148, and 150 in a bridge configuration on corresponding pinned layers 152, 154, 156, and 158, each pinned layer 152, 154, 156, and 158 being magnetized along an in-plane direction. In this third bridge configuration, all sensing elements 144, 146, 148, and 150 have an easy magnetization axis direction orthogonal to the pinning magnetization direction of the pinned layers 152, 154, 156, and 158. The third bridge configuration also includes flux guides 162 and 164 located adjacent to the right edges of sensing elements 146 and 150, respectively, and flux guides 166 and 168 located adjacent to the left edges of sensing elements 144 and 148, respectively. Flux guides 166, 162, 168 and 164 are positioned below sensing elements 144, 146, 148 and 150.

[0031] By positioning the first differential sensor 102 and the second differential sensor 122 orthogonally aligned, with the sensing element orientation of each sensor equally deflected from the pinning direction of the sensor and orthogonal to each other in each sensor, the sensors can detect the component directions of the field applied along the first axis (y-axis) and the second axis (x-axis). Flux guides 162 and 166 are positioned asymmetrically between branches 172 and 170 in the differential sensor 142 below the opposite edges of elements 146 and 144. Flux guide 162 of sensing element 146 guides the magnetic flux from the Z-field into the plane along the right side and rotates the magnetization of sensing element 146 toward higher resistance in a first direction. Similarly, the magnetic flux from the Z-field can be guided into the plane by flux guide 166 along the left side of sensing element 144 and causes the magnetization of sensing element 144 to rotate toward lower resistance in a second direction, opposite to the first direction, because the guide is anti-symmetrical with guide 162. Furthermore, flux guides 164 and 168 are positioned asymmetrically between branches 176 and 174 within the differential sensor 142, below the opposing edges of elements 150 and 148. Flux guide 164 of sensing element 150 guides the magnetic flux from the Z-field into the plane along the right side, rotating the magnetization of sensing element 150 towards higher resistance in a first direction. Similarly, the magnetic flux from the Z-field can be guided into the plane by flux guide 168 along the left side of sensing element 148, rotating the magnetization of sensing element 148 towards lower resistance in a second direction opposite to the first direction, because this guide is anti-symmetrical with guide 164. Therefore, differential sensor 142 can detect the component direction of the field applied along a third axis or vertical axis (z-axis).

[0032] Figure 2A , 2B Figure 2C is a portion of the tunnel magnetoresistive (TMR) sensor device 200. Similar to... Figure 1 How do the differential sensors 102, 122, and 142 detect the component directions of the applied field? The TMR sensor device 200 includes first, second, and third differential sensors configured to detect the component directions of the applied field along a first axis (y-axis), a second axis (x-axis), and a third axis (z-axis), respectively. More specifically, Figure 2A The figure shows a plan view of a portion of the third differential sensor 202 (Z sensor 202) of the TMR device 200. The Z sensor 202 is configured to detect the component direction of a magnetic field applied along the third axis or vertical axis (Z axis).

[0033] exist Figure 2AIn the example shown, the Z sensor 202 includes eight sub-blocks 204A-204H, each of which includes at least one sensing element 216. Figure 2C ), flux guide 218 ( Figure 2C The sensor array 206 comprises an independent flux guide reset coil 208 and an independent sensing element reset coil 210. Additionally, each sub-block 204A-204H is configured to include an independent reset auxiliary coil 212. In some embodiments, the independent flux guide reset coil 208 and independent sensing element reset coil 210 of each sub-block 204A-204H enable the sub-blocks 204A-204H to reset independently of each other between readout cycles of the Z sensor 202. In other embodiments, the independent flux guide reset coil 208, independent sensing element reset coil 210, and independent reset auxiliary coil 212 of each sub-block 204A-204H enable the sub-blocks 204A-204H to reset independently of each other between readout cycles of the Z sensor 202. As an illustrative example, the flux guide reset coil 208, sensing element reset coil 210, and reset auxiliary coil 212 of sub-block 204C enable the corresponding sensing elements 216 and flux guides 218 of sub-block 204C to be reset independently of the corresponding sensing elements 216 and flux guides 218 of other sub-blocks 204A-204B and 204D-204H. In this respect, when the sensing elements 216 and flux guides 218 of sub-block 204C are reset, the sensing elements 216 and flux guides 218 of sub-blocks 204A-204B and 204D-204H are not reset. As another illustrative example, the flux guide reset coil 208, the sensing element reset coil 210, and the reset auxiliary coil 212 enable the respective sensing elements 216 and flux guides 218 of sub-blocks 204A, 204C, 204E, and 204H to be reset independently, while the respective sensing elements 216 and flux guides 218 of sub-blocks 204B, 204D, 204F, and 204G are not reset.

[0034] The positional relationships between the sensor array 206, flux guide reset coil 208, sensing element reset coil 210, and reset auxiliary coil 212 in each of sub-blocks 204A-204H are generally similar from one sub-block to another, and define the orientation of the sub-blocks. For example... Figure 2A As shown, the eight sub-blocks 204A-204H are arranged with horizontal and vertical orientations relative to each other. For example, sub-blocks 204A-204B and 204E-204F are vertically oriented relative to the viewing direction of the figure, while sub-blocks 204C-204D and 204G-204H are vertically oriented relative to each other. Figure 2AThe observation direction is horizontally oriented. Different sub-block orientations mitigate the effects of stress and temperature on the performance of the Z sensor 202 because these effects are averaged together in the anisotropic direction.

[0035] Figure 2B The flux guide reset coil 208 superimposed on sub-block 204A is shown. Figure 2B A flux guide reset coil 208 relative to the sensor array 206 is also shown. In this non-limiting example, the sensor array 206 includes a first region 222A and a second region 222B. The first region 222A includes 384 sensing elements 216, thus having eight sensing elements 216 in each column along the y-axis and forty-eight sensing elements 216 in each row along the x-axis. The second region 222B includes 384 sensing elements 216, thus having eight sensing elements 216 in each column along the y-axis and forty-eight sensing elements 216 in each row along the x-axis.

[0036] The flux guide reset coil 208 is arranged substantially in a plane such that both the effective and ineffective portions of the flux guide reset coil 208 extend along a single plane within sub-block 204A. The effective portion of the flux guide reset coil 208 is configured to apply a first reset field (e.g., a magnetic field) to the sensor array 206. The ineffective portions of the flux guide reset coil 208 connect the effective portions of the flux guide reset coil 208 to each other. Figure 2A In the illustrated embodiment, the flux guide reset coil 208 is positioned below the sensor array 206. In other embodiments, the flux guide reset coil 208 may be positioned above the sensor array 206.

[0037] The flux guide reset coil 208 has a plurality of parallel segments 220A and 220B wired through the sensor array 206. The parallel segments 220A and 220B are oriented orthogonally to the flux guide 218 so that when the flux guide reset coil 208 is energized, a first reset field is generated along the preferred magnetization direction of the flux guide 218. The parallel segments 220A and 220B are wired through the sensor array 206 because each parallel segment 220A and 220B extends along its length close to the flux guide 218 of the sensor array 206, such that the first reset field (in conjunction with...) Figure 2C The described second and third reset fields can orient the magnetization of flux guide 218 to a preferred magnetization direction. In some embodiments, when viewed in a direction perpendicular to the plane in which the flux guide reset coil 208 is arranged, parallel segments 220A and 220B pass directly above or below flux guide 218.

[0038] Each flux guide 218 of the sensor array 206 further includes a first set of flux guides 218 arranged in a first region 222A of the sensor array 206 and a second set of flux guides 218 arranged in a second region 222B of the sensor array 206. In some embodiments, the first region 222A and the second region 222B are symmetrically arranged about a plane 224. The first set of flux guides 218 and the second set of flux guides 218 have corresponding first predetermined magnetization directions 10 that are opposite to each other. Figure 2C ) and the second predetermined magnetization direction 20 ( Figure 2C In some embodiments, the sensing element 216 of the sensor array 206 may include a sensor array 206 with a different bit array configuration, such as a 72×8×2 bit array or any suitable arrangement. Parallel segments 220A of the flux guide reset coil 208 are orthogonally routed through a first set of flux guides 218 in a first region 222A. Parallel segments 220B of the flux guide reset coil 208 are orthogonally routed through a second set of flux guides 218 in a second region 222B.

[0039] Therefore, after performing the flux guide reset operation, the flux guide magnetization orientation of each sub-block 204A-204H is divided into upper and lower portions with opposite orientations. This configuration allows for internal compensation within the sensing transducer for any process-induced asymmetry that results in in-plane stray fields emanating from the flux guide and acting on the sensing element itself. These stray fields act in opposite directions on the top and bottom halves of the sensor bridge, and their influence on the sensing element resistance is eliminated via bridge interconnect wiring that averages the resistance of the sensing elements in the top and bottom halves of one of the sub-blocks 204A-204H.

[0040] The flux guide reset coil 208 also has a plurality of additional segments 220C connecting the first segment 220A and the second segment 220B to each other. These additional segments 220C provide coil wiring between the first segment 220A and the second segment 220B. Figure 2BIn the illustrated embodiment, additional segment 220C is wired through the portion of subblock 204A not occupied by sensor array 206. In some embodiments, these additional segments 220C in these portions of subblock 204A are bound to other metal layers of the substrate to reduce the resistance of flux guide reset coil 208. In some embodiments, the additional segment 220C has a wider or different width (W0) than the parallel segments 220A and 220B (e.g., W1 or W2) to optimize parasitic effects and performance. In yet another embodiment, sensing element 216 and flux guide 218 are also placed in the region close to the additional segment 220C, which contributes to the sensing area of ​​Z sensor 202 and further reduces overall system noise.

[0041] Figure 2B The flux guide reset coil 208 in the depicted embodiment is a planar rectangular coil having an outermost coil portion 226, an innermost coil portion 228, and a plurality of inner turns 230 disposed between the outermost coil portion 226 and the innermost coil portion 228. Figure 2B In the example shown, the flux guide reset coil 208 has a starting segment 220D that extends linearly along the x-axis for a long side length, followed by a first coil segment oriented 90 degrees to the starting segment and extending linearly along the y-axis for a short side length, and then a second coil segment oriented 90 degrees to the first coil segment and extending linearly along the x-axis for another long side length. This pattern continues, with the long and short side lengths becoming shorter after each successive turn around the winding axis to define a rectangular coil.

[0042] exist Figure 2B In the flux guide reset coil 208, an end segment 220E is closer to the winding axis than the start segment 220D. The start segment 220D and at least one immediately following coil segment define the outermost coil portion 226 of the flux guide reset coil 208. The end segment 220E and at least one immediately preceding coil segment define the innermost coil portion 228 of the flux guide reset coil 208.

[0043] Figure 2C It shows relative to Figure 2B The sensor array 206 of sub-block 204A includes the sensing element reset coil 210 and reset auxiliary coil 212. For example... Figure 2CAs shown, the sensing element reset coil 210 and the reset auxiliary coil 212 are configured as separate layers from the flux guide reset coil 208. More specifically, the sensing element reset coil 210 is arranged in a plane substantially spaced apart from the plane in which the flux guide reset coil 208 is arranged. The sensing element reset coil 210 is electrically insulated from the flux guide reset coil 208. The sensing element reset coil 210 is positioned relative to the sensor array 206 to perform a sensing element reset operation, while also being positioned to provide an effective contribution to the total reset field during the flux guide reset operation. Figure 2C In the illustrated embodiment, the sensing element reset coil 210 is positioned above the sensor array 206. In another embodiment, the sensing element reset coil 210 may be positioned below the sensor array 206, in which case the flux guide reset coil 208 would typically be positioned above the sensor array 206.

[0044] The sensing element reset coil 210 has a plurality of parallel segments 232A and 232B wired through the sensor array 206. The parallel segments 232A and 232B are oriented orthogonally to the flux guide 218 so that when the sensing element reset coil 210 is energized during flux guide reset operation, a second reset field is generated along the preferred magnetization direction of the flux guide 218. Additionally, the central axis 30 of each of the parallel segments 232A and 232B is aligned along the x-axis with the center of the corresponding row of sensing elements 216 in the sensor array 206, such that the second reset field eliminates magnetic domains and reduces Barkhausen noise in the sensing elements 216 during sensing element reset operation. The sensing element reset coil 210 also has an additional segment 232C connecting the parallel segments 232A and 232B to each other. The additional segment 232C is wired through the portion of sub-block 204A not occupied by the sensor array 206. Figure 2C The sensing element reset coil 210 in the depicted embodiment is a planar rectangular coil. In some embodiments, the sensing element reset coil 210 has an outermost coil portion, an innermost coil portion, and a plurality of inner turns, so as to resemble a reference coil. Figure 2B The flux guide reset coil 208 is formed into a rectangular coil in the manner described. For example... Figure 2C As shown, the sensing element reset coil 210 is a rectangular coil with a long length along the x-axis and a short length along the y-axis.

[0045] Z-sensor 202 may include a reset auxiliary coil 212. The reset auxiliary coil 212 is substantially arranged in the plane in which the sensing element reset coil 210 is arranged. The reset auxiliary coil 212 is configured to generate additional field uniformity between local strong fields centered on the sensing element 216. The reset auxiliary coil 212 also operates to assist during flux guide reset operations.

[0046] The reset auxiliary coil 212 has multiple parallel segments 234A and 234B wired through the sensor array 206. The parallel segments 234A and 234B are oriented orthogonally to the flux guide 218 so that when the reset auxiliary coil 212 is energized during a flux guide reset operation, a third reset field is generated along the preferred magnetization direction of the flux guide 218. Additionally, the reset auxiliary coil 212 also has an additional segment 234C connecting the parallel segments 234A and 234B to each other. This additional segment 234C is wired through the portion of the sub-block 204A not occupied by the sensor array 206. Figure 2C The reset auxiliary coil 212 in the depicted embodiment is a planar coil, which includes an outermost coil portion, an innermost coil portion, and a plurality of inner turns, in order to resemble the reference. Figure 2B The flux guide reset coil 208 is formed into a rectangular coil in the manner described. For example... Figure 2C As shown, the reset auxiliary coil 212 is a rectangular coil with a long length along the x-axis and a short length along the y-axis.

[0047] The Z-sensor 202 also includes circuitry 214 operably connected to both the flux guide reset coil 208 and the sensing element reset coil 210. Additionally, circuitry 214 is operably connected to a reset auxiliary coil 212. This circuitry 214 is conceptually represented in… Figure 2B and 2C In the circuit 214, there are structures, devices, or techniques configured to control and provide electrical connections to one or more conductive elements, the circuit 214 being operatively associated with or connected to the conductive elements. For example, the circuit 214 of the Z sensor 202 is specifically configured to perform sensing element reset operations and flux guide reset operations independently of each other within each sub-block 204A-204H and independently between different sub-blocks 204A-204H.

[0048] To perform a sensing element reset operation, circuit 214 is configured to excite only the sensing element reset coil 210 to generate a second reset field, such that the total reset field comprises only the second reset field. Circuit 214 is configured to excite at least the effective segment (e.g., parallel segments 220A and 220B) and / or the entire sensing element reset coil 210 during the sensing element reset operation. During this sensing element reset operation, circuit 214 does not excite the flux guide reset coil 208 and / or the reset auxiliary coil 212. Once energized, the sensing element reset coil 210 is configured to generate the second reset field to orient the magnetization of the sensing element 216 to a predetermined state without altering the magnetization of the flux guide 218. The second reset field itself is sufficient to eliminate magnetic domains and reduce Barkhausen noise in the sensing element 216 without changing the preferred magnetization direction of the flux guide 218. In this respect, the sensing element reset coil 210 is optimized for a high peak field to minimize the current required during the sensing element reset operation.

[0049] To perform the flux guide reset operation, in some embodiments, circuit 214 is configured to energize both flux guide reset coil 208 and sensing element reset coil 210 to generate a first reset field around flux guide reset coil 208 and a second reset field around sensing element reset coil 210, respectively. Circuit 214 is configured to energize at least effective segments (e.g., parallel segments 220A and 220B) of flux guide reset coil 208 and effective segments (e.g., parallel segments 232A and 232B) of sensing element reset coil 210. Circuit 214 is configured to energize the entire flux guide reset coil 208 and the entire sensing element reset coil 210. The first and second reset fields combine to establish a total reset field sufficient to orient the magnetization direction of flux guide 218 to a known, previously calibrated state, which may be interchangeably referred to as a predetermined magnetization direction / orientation of the flux guide or a predetermined flux guide magnetization direction / orientation. In this regard, the flux guide reset coil 208 is optimized for low resistance and magnetic field uniformity.

[0050] Furthermore, in other embodiments for performing flux guide reset operations, circuit 214 is configured to excite flux guide reset coil 208, sensing element reset coil 210, and reset auxiliary coil 212, respectively. In this regard, circuit 214 is configured to excite at least the effective segments of flux guide reset coil 208 (e.g., parallel segments 220A and 220B), the effective segments of sensing element reset coil 210 (e.g., parallel segments 232A and 232B), and the effective segments of reset auxiliary coil 212 (e.g., parallel segments 234A and 234B). Circuit 214 is configured to excite the entire flux guide reset coil 208, the entire sensing element reset coil 210, and the entire reset auxiliary coil 212. When excited, reset auxiliary coil 212 is configured to generate a third reset field around reset auxiliary coil 212. The third reset field is configured to smooth the first reset field around one or more flux guides 218, which helps to orient the magnetization direction of flux guides 218 during flux guide reset operations. With this configuration, circuit 214 is configured to activate flux guide reset coil 208, sensing element reset coil 210, and reset auxiliary coil 212 to generate first, second, and third reset fields that combine to establish a total reset field sufficient to orient the magnetization of flux guide 218 to a known, previously calibrated state.

[0051] Figure 3 This is a cross-sectional view showing a portion of a sensor structure 300 according to an example embodiment. The sensor structure 300 integrates transistor technology with magnetoresistive technology (such as TMR technology) on a single chip. For example, in Figure 3 In the sensor structure 300, a transistor assembly 302 and a magnetoresistive sensor assembly 304 are stacked relative to a substrate 306. The transistor assembly 302 and the magnetoresistive sensor assembly 304 are operatively connected to each other.

[0052] The transistor assembly 302 includes at least circuitry 214 configured to activate a flux guide reset mechanism of the magnetoresistive sensor assembly 304 to establish a total reset field sufficient to orient the magnetization of at least one flux guide 312 to a known, previously calibrated state. Additionally, the transistor assembly 302 includes circuitry 214 configured to activate a sensing element reset circuitry of the magnetoresistive sensor assembly 304 to establish a reset field sufficient to reset one or more sensing elements 314. For example, in Figure 3In this embodiment, circuit 214 includes at least a complementary metal-oxide-semiconductor (CMOS) device 308. Sensor structure 300 may also include a metal-insulator-metal (MIM) device 310, which may be part of circuit 214 or part of signal amplification circuitry for the sensor structure. CMOS device 308 includes at least standard CMOS components. The compatibility of TMR technology with CMOS device 308 provides enhanced sensitivity with a relatively large linear sensing range and relatively low noise. Furthermore, transistor assembly 302 and / or CMOS device 308 include one or more of metal layers 316. As a non-limiting example, Figure 3 The illustration shows a transistor assembly 302 and / or a CMOS device 308, which includes at least a first metal layer M1, a second metal layer M2, a third metal layer M3, and a fourth metal layer M4. Each metal layer 316 is insulated within an insulating portion 318, the insulating portion 318 including at least... Figure 3 One or more insulating layers are shown. The insulating portion 318 also insulates the contact 346 and the vertical interconnect 320 (or via 320), which operatively connects one or more metal layers 316 and the CMOS device 308 to each other. The contact 346 provides an electrical connection between a substrate 306 comprising a semiconductor (e.g., silicon) and the first metal layer M1. The plurality of vertical interconnects 320 includes any suitable number of vertical interconnects 320. For example, in... Figure 3 In this configuration, the plurality of vertical interconnect portions 320 include at least a first vertical interconnect portion VIA1, a second vertical interconnect portion VIA2, a third vertical interconnect portion VIA3, and a fourth vertical interconnect portion VIA4. (See reference) Figure 3 As an example, the upper metal layer (e.g., the fourth metal layer M4) is configured to be connected to the magnetoresistive sensor assembly 304 via an upper vertical interconnect 320 (e.g., VIA4). Additionally, within the insulating portion 318, the transistor assembly 302 includes at least one nearby MIM device 310 within the metal layer 316. For example, in Figure 3 In this context, the MIM device 310 is a capacitor top metal (CTM) device disposed in an insulating portion 318 between the third metal layer M3 and the fourth metal layer M4. At this point, the MIM device 310 is operatively connected to the CMOS device 308 via a metal layer 316 and a vertical interconnect portion 320.

[0053] The magnetoresistive sensor assembly 304 includes at least a TMR device configured as a Z sensor 202. For example, Figure 3 The illustration shows a conceptual cross-sectional view of a portion of a TMR device, including a view of at least one sensing element 314, which corresponds to... Figure 2CAt least one of the sensing elements 216 in the sensor array 206. The TMR device is configured to detect the component direction of a magnetic field applied along the third axis or z-axis. Additionally, the TMR device includes a flux guide 312 and a flux guide reset mechanism. The flux guide reset mechanism includes at least a first reset component and a second reset component. Furthermore, the flux guide reset mechanism may include at least one other reset component, such as a third reset component, disposed within the same dielectric as the second reset component, and... Figure 3 It is not visible in the cross-section shown.

[0054] The first reset component includes at least an ultra-thick metal (UTM) coil as a first coil 322, which is configured as a flux guide reset coil 208. Figure 2A (and it is constructed to include coils of any suitable shape and configuration. As a non-limiting example, in) Figure 2A In the flux guide reset coil 208, a rectangular coil configuration is included relative to a top plan view. The second reset component includes at least a portion of a metal global interconnect (MGI) element as a second coil 324, which is configured as a sensing element reset coil 210. Figure 2C ), and is constructed to include coils of any suitable shape and configuration. As a non-limiting example, in Figure 2A In the top view, the sensing element reset coil 210 includes a rectangular coil configuration. Furthermore, although not shown in this cross-sectional view, the third reset component includes an MGI auxiliary element as a third reset coil 326, which is configured as a reset auxiliary coil 212. Figure 2C ), and is constructed to include coils of any suitable shape and configuration. As a non-limiting example, in Figure 2C In the top plan view, the reset auxiliary coil 212 includes a rectangular coil configuration. At least as... Figure 3 As shown, flux guide 312 is disposed between a dielectric layer 330 containing a first reset component (e.g., first coil 322) and another dielectric layer 330 containing both a second reset component (e.g., second coil 324) and a third reset component (e.g., third coil 326). Furthermore, in this example, flux guide 312 is configured to penetrate into at least the dielectric layer 330 containing the first reset component (e.g., first coil 322). As a non-limiting example, dielectric layer 330 comprises tetraethoxysilane (TEOS), any suitable dielectric material, or any combination thereof.

[0055] In response to communication with transistor assembly 302, flux conductor reset mechanism is configured to perform a reset operation to position the magnetization of flux conductor 312 to a predetermined magnetic orientation or default setting. More specifically, flux conductor reset mechanism is advantageously configured to perform the reset operation with a voltage suitable for various applications, including, for example, mobile and smartphone applications.

[0056] Additionally, the magnetoresistive sensor assembly 304 includes a vertical interconnect 328 disposed within the dielectric layer 330, which is located on the first coil 322. The vertical interconnect 328 operatively connects the first coil 322 to the metal wire 332. Figure 3 In this configuration, metal wire 332 may comprise copper, aluminum, or any suitable metal. Metal wire 332 is connected to a magnetic tunnel junction (MTJ) element via vertical interconnect 328. The MTJ element includes a magnetic reference element 334 (or pinning element) and a sensing element 314. The sensing element 314 provides a resistance change in response to a field. The MTJ element is connected to a local interconnect 336 via vertical interconnect 328. Additionally, a second coil 324 is connected to metal wire 332 via vertical interconnect 328. The second coil 324 may be connected to a thick metal pad finishing piece 340. In this example, the thick metal pad finishing piece 340 comprises aluminum, any suitable metal, or any suitable combination thereof. Furthermore, as... Figure 3 As shown, the sensor structure 300 includes several dielectric layers 330 located between various components. Additionally, depending on the material used (e.g., a metal such as copper), the sensor structure 300 may include multiple etch stop layers 338 of suitable thickness between these various components, such as... Figure 3 As shown. As a non-limiting example, the etch stop layer 338 comprises silicon nitride (SiN), any suitable etch stop material, or any combination thereof. The magnetoresistive sensor assembly 304 also includes a passivation layer 348 configured to protect the chip. In this example, the passivation layer 348 comprises at least one dielectric layer 330, at least one silicon nitride layer 338, and at least one silicon oxynitride (SiON) layer 344. The passivation layer 348 includes at least one opening 342 that exposes the thick metal pad finishing piece 340 for electrical access thereto.

[0057] Figure 4A , Figure 4B and Figure 4C This is a conceptual diagram providing a general overview of the configuration of the magnetoresistive sensor assembly 304. More specifically, Figure 4A This shows the magnetoresistive sensor assembly 304 and... Figure 4B and 4C A conceptual diagram of the selection of cross-sectional views related to the graphic data. Figure 4A It is a cross section taken along the yz plane corresponding to the y-axis and z-axis.

[0058] exist Figure 4A In the diagram, a magnetoresistive sensor assembly 304 is shown having a sensing element 314 disposed in a dielectric layer 330 on a flux guide 312. The flux guide 312 is configured to guide magnetic flux to the sensing element 314. The flux guide 312 is positioned adjacent to the sensing element 314. Additionally, the magnetoresistive sensor assembly 304 includes a flux guide reset mechanism configured to set the flux guide 312 to a predetermined magnetic orientation. The flux guide reset mechanism includes a first segment 400 and a second segment 402. Both the flux guide 312 and the sensing element 314 are disposed between the first segment 400 and the second segment 402.

[0059] A first segment 400 is disposed on a first side 404 of the flux guide. The first segment 400 is disposed on a first side of the sensing element 314. The first segment 400 includes a first coil 322, which is configured as a flux guide reset coil 208. The first coil 322 includes a plurality of first coil segments 322A. The first coil 322 is disposed within at least one dielectric layer 330. Figure 3 As shown, the dielectric layer 330 is configured to partially insulate the first coil 322. Additionally, Figure 4A A cross-section of the first coil segment 322A is shown, its length extending perpendicular to the length of the flux guide 312. Each first coil segment 322A has a width W1 and a thickness T1. Furthermore, as... Figure 4A As shown, a distance D1 (e.g., pitch or dielectric constant) exists between adjacent first coil segments 322A. This arrangement of the first coil segments 322A is made possible by having a relatively low resistivity. Figure 4A In the first coil segment 322A, therein, at least aluminum or any suitable material that enables the provision of similar results as discussed herein.

[0060] The second segment 402 is disposed on the second side 406 of the flux guide 312. The second segment 402 is disposed on the second side of the sensing element 314. Each sensing element 314 has a width W2 and a thickness T2. Furthermore, a distance D2 exists between adjacent sensing elements 314. Figure 4A As shown, the flux guide 312 is larger than the sensing element group 314 along the y-axis, such that the end portion of the flux guide 312 does not overlap with the sensing elements 314. This feature ensures that each sensing element 314 is not completely covered by the flux guide 312, thereby ensuring that magnetic flux is guided to the sensing element 314 by at least the inner region 408, while the outer region 410 provides additional margin.

[0061] The second section 402 includes the second coil 324 and the third coil 326. Figure 4AThe cross-sections of a second coil segment 324A and a third coil segment 326A are shown, having lengths that are parallel to each other and perpendicular to the length of the flux guide 312. Each second coil segment 324A has a width W3 and a thickness T3. Additionally, each third coil segment 326A has a width W4 and a thickness T4. Furthermore, the thickness T3 of the second coil segment 324A is the same as or substantially the same as the thickness T4 of the third coil segment 326A. Moreover, in this example, the second coil segment 324A and the third coil segment 326A are on the same layer. In this example, the dimensions (e.g., W1 and T1) of each first coil segment 322A are larger than the dimensions (e.g., W3 and T3) of each second coil segment 324A. Furthermore, in this example, the dimensions (e.g., W1 and T1) of each first coil segment 322A are larger than the dimensions (e.g., W4 and T4) of each third coil segment 326A. In this example, the pitch (W1+D1) of the first coil segment 322A is different from the pitch (W2+D2) of the second coil segment 324A.

[0062] In addition, such as Figure 4A As shown, there is a distance D3 between adjacent second coil segments 324A. Additionally, there is a distance D4 between adjacent third coil segments 326A within the inner region 408, and a distance D5 between adjacent third coil segments 326A within the outer region 410. A distance D6 exists between (i) adjacent second coil segments 324A and third coil segments 326A, or (ii) adjacent third coil segments 326A and second coil segments 324A. Each distance ensures a sufficient amount of at least one dielectric layer 330 between any pair of adjacent coil segments. Furthermore, in this example, distance D4 is greater than distance D5 because adjacent third coil segments 326A in the inner region 408 include second coil segments 324A interleaved between adjacent third coil segments 326A. Meanwhile, in this example, distance D5 is similar or substantially similar in length to distance D6.

[0063] Additionally, there are inner region 408 and outer region 410 associated with flux guide 312. Inner region 408 corresponds to the portion overlapping with sensing element 314. Inner region 408 may be defined at least by the end surfaces of the first sensing element 314 and the last sensing element 314. The first and last sensing elements 314 are part of a set of sensing elements 314 aligned along an axis parallel to the y-axis. At this point, inner region 408 of second segment 402 overlaps with the corresponding inner region 408 of flux guide 312. Inner region 408 of flux guide 312 includes the central portion of flux guide 312.

[0064] The internal region 408 has a layout including a third coil segment 326A, which is interleaved with the second coil segment 324A, such that the two coils are arranged in an alternating pattern, as shown below. Figure 4A As shown. In this internal region 408, each second coil segment 324A is associated with and aligned with a corresponding one of the sensing elements 314. As described above, the central axis 30 of each second coil segment 324A is aligned with the central portion of the corresponding sensing element 314. This correspondence provides at least a one-to-one relationship between the second coil segment 324A and the sensing element 314. The second coil 324 is configured to be energized segmentally and sequentially during a sensing element reset operation, and is configured to be simultaneously energized together with other coils during a flux guide reset operation. This feature is advantageous because the second coil 324 or portions thereof are configured to provide a sensing element reset function when activated as a sensing element reset circuit, and are also configured to provide a flux guide reset function when activated as a flux guide reset mechanism.

[0065] The outer region 410 extends from the inner region 408 toward the edges 412 and 414 of the flow guide 312. The outer region 410 of the flow guide 312 includes the edges 412 and 414 of the flow guide 312, such as... Figure 4A As shown. The outer region 410 of the second segment 402 corresponds to the portion around the flux guide 312 that does not overlap with the sensing element 314. The outer region 410 can be defined from the edge of the sensing element 314 in a row of the sensor array 206 toward the flux guide 312. The outer region 410 has a layout including third coil segments 326A arranged adjacent to each other. For example, in Figure 4A In this example, the outer region 410 includes two loops of the third coil 326 on the outermost segment 416 of the second coil segment 324A. The outer region 410 is configured with a set of third coil segments 326A. Figure 4A As shown, this group includes the innermost segment 418 and the adjacent segment 420.

[0066] Figure 4B and 4C The in-plane component (y-axis component) of the magnetic field distribution is shown, which is sampled in the central region of the flux guide 312. Typically, the graph ( Figure 4B-4CFigures 5B-5C, 6B-6C, 7B-7C, and 8B illustrate the relationship between magnetic flux density values ​​in millitalas (mT) or teslas (T) along the y-axis and distances in meters (m) along the x-axis along the flux guide 312. In these non-limiting examples, the reference value 0 used as the basis for distance calculation is obtained at a position along the flux guide 312 corresponding to the center of the rightmost turn of the second coil 324. The graphs also include a first reference line 422 to indicate the position of the left edge 412 of the flux guide 312, and a second reference line 424 to indicate the position of the right edge 414 of the flux guide 312. Additionally, some graphs ( Figure 4C and 5C This includes a third reference line 426 to indicate the threshold (e.g., magnetic flux density value) within which the flux guide reset operation is fully performed.

[0067] Figure 4B The magnetic field distributions 428 of the first coil 322, 430 of the second coil 324, and 432 of the third coil 326 are illustrated when driven by a 10 mA current and when sampling is performed at the central region of the flux guide 312. In this respect, Figure 4A The configuration requires a relatively high current to provide a total magnetic field distribution that meets the threshold (e.g., 17.5 mT) 434, as reference line 426 ( Figure 4C As indicated by ), to be used to perform a flux guide reset operation. For example, in Figure 4B and 4C In this configuration, the first coil 322 is supplied with 170mA, the second coil 324 is supplied with 270mA, and the third coil 326 is supplied with 26mA. For example... Figure 4B and 4C As shown, the variation in the total magnetic field distribution 434 relative to the threshold indicated by reference line 426 results in some wasted energy. Additionally, as... Figure 4C As shown, the total magnetic field distribution 434 has magnetic flux density values ​​436 and 438 that are significantly below the threshold at the edges 412 and 414, resulting in the flux guide resetting operation being less effective at the outer region 410 of the flux guide 312 compared to the inner region 408 of the flux guide 312.

[0068] Figure 5A , 5B Figure 5C illustrates a different configuration associated with the magnetoresistive sensor assembly 304. More specifically, Figure 5A This shows the magnetoresistive sensor assembly 304 and... Figure 5B and 5CA conceptual diagram of a cross-section related to the graphic data. Regarding the first section 400 of the sensing element 314, the flux guide 312, and the flux guide reset mechanism... Figure 5A The configuration is similar to Figure 4A .However, Figure 5A The second section 402 of the flux guiding mechanism is different Figure 4A The second section of the throughput guide mechanism.

[0069] exist Figure 5A In the second section 402, there are an inner region 408 and an outer region 410. The inner region 408 has a layout including a third coil segment 326A, which is interleaved with the second coil segment 324A, such that the second coil 324 and the third coil 326A are arranged in an alternating pattern, as shown below. Figure 5A As shown. In this internal region 408, each second coil segment 324A is associated with and aligned with a corresponding one of the sensing elements 314. At this point, Figure 5A Internal area 408 and Figure 4A The internal regions 408 are the same or substantially similar. Meanwhile, Figure 5A The outer region 410 is different Figure 4A The outer region 410.

[0070] exist Figure 5A In this example, the outer region 410 has a layout including a group of third coil segments 326A arranged adjacent to each other. In this example, the outer region 410 includes three loops of the third coil 326 on the outermost segment 416 of the second coil segment 324A. More specifically, in this example, the group of third coil segments 326A includes at least the innermost segment 418 and the adjacent segment 420, as previously described. Additionally, regarding the outer region 410, the group of third coil segments 326A includes the outermost segment 500, which is positioned on the outer side of the adjacent segment 420, as... Figure 5A As shown.

[0071] Figure 5B and 5C The in-plane component (y-axis component) of the magnetic field distribution is shown, which is sampled in the central region of the flux guide 312. More specifically, Figure 5B The magnetic field distributions 502 of the first coil 322, 504 of the second coil 324, and 506 of the third coil 326 are illustrated when driven by a suitable current and when sampling is performed at the central region of the flux guide 312. As a non-limiting example, in Figure 5B In the first coil segment 322A, the current is driven by 170mA; the second coil segment 324A is driven by 27mA; and the third coil segment 326A is driven by 22mA.

[0072] like Figures 5A-5C As shown, this set of third coil segments 326A is configured such that the flux guide reset mechanism can provide a total magnetic field distribution 508, which has a magnetic flux density value 510 at one end portion of the flux guide 312 and a magnetic flux density value 512 at the opposite end portion of the flux guide 312, the magnetic flux density value 512 being closer to a threshold, so that the flux guide reset operation is performed more efficiently and uniformly across the length of the flux guide 312. The arrangement of this set of third coil segments 326A in the outer region 410 is configured to provide a magnetic flux density value ( ) at the crest 514. Figure 5B The magnetic flux density value is substantially greater than the magnetic flux density value at peak 516 of the arrangement of the third coil segment 326A in the inner region 408. Figure 5B In this configuration, Figure 5A The third coil 326 is driven by less than Figure 4A The third coil 326 is driven by a current (e.g., 26 mA) or a current (e.g., 22 mA), thereby increasing the total magnetic flux density value at the edges 412 and 414 of the flux guide. The third coil 326 is configured to provide a relatively high magnetic field by providing a continuous pattern of adjacent third coil segments 326A at the end portions of the flux guide 312. Figure 5B This allows the magnetic field to provide a total magnetic field enhancement, which results in magnetic flux density values ​​510 and 512 (e.g., 15.5 mT) at these end portions of the flux guide 312 being higher than those provided by the flux guide 312. Figure 4A The coil configuration at the edges 412, 414 of the flux guide 312 provides a total magnetic field distribution 434 that provides flux density values ​​436 and 438 (e.g., 13 mT) that are closer to the threshold, as indicated by reference line 426. At this point, Figure 5A The observed peak field gain of the configuration is Figure 4A The observed peak field gain of the configuration is approximately 13%, because with Figure 4A Compared to the peak magnetic flux density of 2mT / 10mA in the third coil 326, Figure 5A The peak magnetic flux density of the third coil 326 is 2.25 mT / 10 mA. This increase in the observed peak magnetic field of the third coil 326 increases the total magnetic flux density values ​​510 and 512 near the end portion of the flux guide 312, and at least offsets the reduction in the second magnetic field at the outer region 410 due to the absence of the second coil 324 in the outer region 410.

[0073] exist Figure 4A and Figure 5AGiven general design wiring rules, the first coil segment 322A cannot be constructed with a spacing (D1+W1) equal to the spacing (D2+W2) of the sensing element 314. Therefore, Figure 4A and Figure 5A The example cannot provide coherence between the magnetic field distribution 428 / 502 of the first coil 322 and the magnetic field distribution 430 / 504 of the second coil 324, which is arranged relative to the sensing element 314. In contrast, as Figure 6A-9 As shown in the provided example, when the first coil 322 is configured to have the same or substantially the same pitch as the sensing element 314, the first coil 322 is then configured to have the same or substantially the same pitch as the second coil 324. When the first coil 322 is configured to have the same pitch as the second coil 324, the first coil 322 is then configured to generate a magnetic field distribution coherent with the magnetic field of the second coil 324, such that the entire magnetic field distribution is flattened on the flux guide, thereby reducing the power consumption of the sensor structure 300.

[0074] Figure 6A , Figure 6B and Figure 6C The diagram illustrates another configuration associated with a flux reset mechanism, which can provide a ratio to the first coil 322. Figure 4A or Figure 5A The finer wiring of the first coil 322 is achieved through process adjustments. This may involve process optimization and / or switching to an alternative interconnect technology (i.e., copper processing). This process adjustment facilitates reducing the distance between the first coil 322 and the flux guide 312 from distance D8 to distance D9. Additionally, this process adjustment facilitates enabling the first coil 322 to be constructed from a thickness T1 (including aluminum) of the first coil segment 322A. Figure 4A and Figure 5A The thickness T5 is reduced to include the first coil segment 322B of copper. Figure 6A , Figure 7A , Figure 8A and Figure 9 Furthermore, when used in the design of the first coil 322, this process adjustment provides the wiring resistivity of the copper process, which is essentially similar to the wiring resistivity of the aluminum process.

[0075] Figure 6A This is a conceptual diagram showing the relationship between the magnetoresistive sensor assembly 304 and... Figure 6B and 6C The selection of the relevant parts of the graphic data is shown in the cross-sectional view of the relevant flux guide reset mechanism. Regarding the sensing element 314, flux guide 312, and the second section 402 of the flux guide reset mechanism, Figure 6A The configuration is similar to Figure 4A .However, Figure 6A The first section 400 of the flux guiding mechanism is different Figure 4A The first section 400 of the throughput guiding mechanism.

[0076] The first section 400 includes multiple loops and turns of a first coil 322, which is configured to provide a first magnetic field (having a first magnetic field distribution 600) to the flux guide 312 during a flux guide reset operation. For example, in Figure 6A In the first section 400, a relatively close arrangement of turns of a first coil 322 is included to provide a first coil segment 322B. Each first coil segment 322B includes a width W5 and a thickness T5. In this respect, as... Figure 6A As shown, width W5 is greater than width W3. Width W5 is greater than width W4. Thickness T5 is greater than thickness T3. Thickness T5 is greater than thickness T4. The first coil 322 is arranged at a distance D7 between adjacent first coil segments 322B along the length of flux guide 312. Distance D7 is greater than distance D5. Distance D7 is greater than distance D6. Figure 6A The distance D7 between adjacent first coil segments 322B in the first segment 400 is less than Figure 4A The distance D1 between adjacent first coil segments 322A in the first segment 400. At this point, Figure 6A The first coil 322 has a ratio Figure 4A The first coil 322 has a more compact coil configuration. Figure 6A A key aspect of the configuration of the first coil 322 is that its pitch (W5+D7) is arranged to be the same as the pitch of the sensing element 314. Furthermore, in Figure 6A In this configuration, the pitch (W5+D7) of the first coil segment 322B (or the adjacent turns of the first coil 322) is configured to be the same as the pitch (W3+D3) of the second coil segment 324A (or the adjacent turns of the second coil 324). In this respect, process adjustments are made to allow the turns of the first coil 322 (or the first coil segment 322B) to be placed at the same pitch as the turns of the second coil 324, while offset by half a pitch, thereby generating magnetic field distributions 600 and 602 that are offset by half a cycle relative to each other.

[0077] in addition, Figure 6A The dimensions of each first coil segment 322B are different Figure 4A The dimensions of each first coil segment are 322A. For example, Figure 6A The width W5 of the first coil segment 322B is less than Figure 4A The width W1 of the first coil segment 322A. Additionally, Figure 6A The thickness T5 of the first coil segment 322B is less than Figure 4A The thickness T1 of the first coil segment 322A. Furthermore... Figure 6AThe number of first coil segments 322B in the first segment 400 is greater than Figure 4A The number of first coil segments 322A in the first segment 400. As a non-limiting example, for example, Figure 6A The length of flux guide 312 includes 11 first coil segments 322B, while Figure 4A The example, along the length of flux guide 312, includes seven first coil segments 322A. This arrangement of first coil segments 322B relative to the flux guide is made possible by having relatively low resistivity. For example, in Figure 6A In this configuration, the first coil segment 322B comprises at least copper or any suitable material capable of providing similar results as discussed herein. Furthermore, as stated above, Figure 6A The configuration of the first coil 322 is advantageous because the distance D9 between the first coil segment 322B and the flux guide 312 is less than the distance D8 between the first coil segment 322A and the flux guide 312.

[0078] Figure 6B and 6C The in-plane component (y-axis component) of the magnetic field distribution is shown, which is sampled at the central region of the flux guide 312. More specifically, Figure 6B The diagrams illustrate the first magnetic field distribution 600 of the first coil 322, the second magnetic field distribution 602 of the second coil 324, and the third magnetic field distribution 604 of the third coil 326 when driven by a suitable current and when sampling is performed at the central region of the flux guide 312. As a non-limiting example, in... Figure 6B In this configuration, the first coil segment 322B is driven by 110mA, the second coil segment 324A by 27mA, and the third coil segment 326A by 9mA. For example... Figure 6B As shown, the peak value (or crest) of the magnetic field distribution 600 generated by the first coil 322 deviates from the peak value (or crest) of the magnetic field distribution 602 generated by the second coil 324. Due to this coherent combination and the reduction in the thickness T5 of the first coil segment 322B (compared to the thickness T1 of the first coil segment 322A (comprising aluminum), the driving... Figure 6A The current ratio required for the coil configuration to drive Figure 4A or Figure 5A The coil configuration requires 40% less current. Figure 6A The coil configuration also provides an average magnetic field of 120 mT / A, which is for Figure 4A Improvements to the coil configuration, Figure 4A The coil configuration provides an average magnetic field of 70 mT / A.

[0079] in addition, Figure 6B The first magnetic field distribution 600 and Figure 4BA comparison of the first magnetic field distribution 428 reveals that, with Figure 4A Compared to the configuration of the first coil segment 322A, Figure 6A The configuration of the first coil segment 322B imparts a difference in the length of the flux guide 312. Figure 6A The average first magnetic field distribution generated by the first coil segment 322B is greater than 600. Figure 4A The average first magnetic field distribution of the first coil segment 322A is 428. Furthermore, in... Figure 6A Within the internal region 408, the first coil segment 322B is configured relative to the second coil segment 324A to generate a first magnetic field distribution 600 coherent with the second magnetic field distribution 602. Additionally, in Figure 6A Within the internal region 408, the first coil segment 322B is configured relative to the third coil segment 326A to generate a first magnetic field distribution 600 coherent with the third magnetic field distribution 604. More specifically, within the internal region 408, the first coil segment 322B is configured relative to the second coil segment 324A such that at least one set of troughs in the first magnetic field distribution 600 coincides with a set of peaks in the second magnetic field distribution 602. Furthermore, within the internal region 408, the first coil segment 322B is configured relative to the third coil segment 326A such that at least one set of peaks in the first magnetic field distribution 600 coincides with at least one set of peaks in the third magnetic field distribution 604. Simultaneously, at least for the internal region 408, at least due to the interleaving of the second coil segment 324A and the third coil segment 326A, the set of peaks in the second magnetic field distribution 602 and the set of peaks in the third magnetic field distribution 604 provide an alternating pattern, such as... Figure 6B As shown.

[0080] Figure 6C The diagram illustrates the total magnetic field distribution 606, which is generated by a combination of the first magnetic field distribution 600 of the first coil 322, the second magnetic field distribution 602 of the second coil 324, and the third magnetic field distribution 604 of the third coil 326. Figure 6C The total magnetic field distribution 606 is shown to exhibit a plateau or similar shape within the internal region 408 of the flux guide 312. This plateau facilitates a relatively stable and uniform magnetic flux density at the internal region 408 of the flux guide 312, which coincides with the sensing element 314. Figure 6C In the middle, the total magnetic field distribution 606 is slightly above the threshold (e.g., 17.5 mT), even when configured to drive Figure 4A Compared to the higher current configuration of the coil, Figure 6A The coil configuration is set to be driven by relatively low current (e.g., 9mA for the first coil 322 and 110A for the third coil 326).

[0081] Figure 7A , 7BFigure 7C illustrates a diagram associated with another configuration of the flux reset mechanism. More specifically, Figure 7A This shows the magnetoresistive sensor assembly 304 and... Figure 7B and 7C A conceptual diagram of a cross-sectional view showing the selection of parts related to the graphic data. Regarding the sensing element 314 and the flux guide 312, Figure 7A The configuration is similar to Figure 4A .However, Figure 7A The flux guide reset mechanism is different Figure 4A The flux guide mechanism. More specifically, the flux guide reset mechanism is provided with a configuration in... Figure 5A The second coil 324 and the third coil 326 are arranged together in the second section 402. Figure 6A The first coil 322 is located within the first section 400. This flux guide reset mechanism is advantageously configured to provide magnetic field enhancement via a set of third coil segments 326A at the outer region 410, and also advantageously configured to provide coherence between the magnetic field distributions of the first coil 322, the second coil 324, and the third coil 326 at the inner region 408. These features contribute to a more stable and uniform overall magnetic field effect along the entire length of the flux guide 312.

[0082] Figure 7B and 7C The in-plane component (y-axis component) of the magnetic field distribution is shown, which is sampled at the central region of the flux guide 312. More specifically, Figure 7B The diagram illustrates the magnetic field distribution 700 of the first coil 322, the magnetic field distribution 702 of the second coil 324, and the magnetic field distribution 704 of the third coil 326 when driven by a suitable current. As a non-limiting example, in... Figure 7B In this configuration, the first coil segment 322B is driven by 115mA, the second coil segment 324A by 16mA, and the third coil segment 326A by 22mA. Meanwhile, Figure 7C The diagram illustrates the total magnetic field distribution 706, which is generated by a combination of the magnetic field distribution 700 of the first coil 322, the magnetic field distribution 702 of the second coil 324, and the magnetic field distribution 704 of the third coil 326, as shown. Figure 7B As shown. Reference Figure 7C The total magnetic field distribution 706 exhibits a higher performance than... Figure 4C The total magnetic field of 434 results in less energy waste and less noticeable ripples. Furthermore, Figure 7A The configuration facilitates providing magnetic flux density values ​​708 and 710 at the end portion of the flux guide 312, which are closer to the threshold used to perform the flux guide reset operation. Figures 7A-7C In the middle, the total magnetic field distribution of 706 is slightly above the threshold (e.g., 17.5 mT), even with Figure 4A The configuration is compared to the 170mA drive for the first coil 322 and the 26mA drive for the third coil 326. Figure 7A The configuration is driven by a low current, such as 115mA for the first coil 322 and 22mA for the third coil 326.

[0083] Figure 8A and 8B The diagram illustrates an alternative configuration associated with the flux guide reset mechanism. More specifically, Figure 8A This shows the magnetoresistive sensor assembly 304 and... Figure 8B A conceptual diagram of a cross-section related to the graphic data. Regarding the first section 400 of the sensing element 314, the flux guide 312, and the flux guide reset mechanism... Figure 8A The configuration is similar to Figure 6A .However, Figure 8A The second section 402 of the flux guiding mechanism is different Figure 6A The second section 402 of the flux guiding mechanism. In this respect, for example, Figure 8A The flux guide mechanism does not include and / or uses a third coil 326 for flux guide reset operations, while Figure 6A The flux guide mechanism includes and uses a third coil 326 for flux guide reset operation.

[0084] exist Figure 8A In the second segment 402, there are an inner region 408 and an outer region 410. The inner region 408 corresponds to the portion that overlaps with the sensing element 314. The inner region 408 has a layout that includes a second coil segment 324A, the configuration of which is similar to that of the second coil segment 324A in terms of its width W3, thickness T3, and distance D3 between adjacent second coil segments 324A. Figure 6A The configuration. As described above, in this internal region 408, each second coil segment 324A is associated with and aligned with a corresponding one of the sensing elements 314. However, with Figure 6A Compared to the second section 402, Figure 8A The second section 402 does not include the third coil 326, at least not within the internal region 408. Figure 8A In the second section 402, there is a layout of a second coil segment 324A located within the dielectric layer 330, such that only a portion of the dielectric layer 330 is located between adjacent second coil segments 324A along the y-axis.

[0085] The outer region 410 corresponds to the portion above the flux guide 312 that does not overlap with the sensing element 314. Figure 8A The outer region 410 is also different Figure 6A The outer region 410. For example... Figure 8AAs shown, the outer region 410 of the second segment 402 includes only at least one dielectric layer 330. The outer region 410 of the second segment 402 does not include the second coil segment 324A. The outer region 410 of the second segment 402 also does not include the third coil segment 326A. At this point, the outer region 410 of the second segment 402 does not include any coil segment. In the outer region 410, the flux guide 312 overlaps with the first coil segment 322B and at least one dielectric layer 330 in the first segment 400, and only with at least one dielectric layer 330 in the second segment 402. This provides a simple configuration that saves material.

[0086] Figure 8B The diagram illustrates the in-plane components (y-axis components) of the total magnetic field distribution at 80°, which are derived from... Figure 8A The magnetic field distribution of the first coil 322 and Figure 8A The combination of the magnetic field distributions of the second coil 324 generates the magnetic field distribution, wherein each will have a magnetic field distribution similar to that of the first magnetic field distribution 600 and the second magnetic field distribution 602, at least in Figure 6B As shown in the image. Figure 8B It shows at least with Figure 4C Compared to the total magnetic field 434, the total magnetic field distribution 800 exhibits a plateau region with less wasted energy and less noticeable ripples. However, at least because the second section 402 does not have any coils in the outer region 410 (i.e., no second coil section 324A and third coil section 326A), the total magnetic field 800 has relatively low magnetic flux density values ​​802 and 804 at the end portions of the flux guide 312. Figure 8A The configuration provides a relatively simple flux guide reset mechanism, which is configured to provide a relatively stable and uniform flux guide reset operation that satisfies a threshold at least relative to the internal region 408 where the sensing element 314 is located.

[0087] Figure 9 This is a conceptual cross-sectional view of a sixth example of a flux guide reset mechanism related to a sensing element and a flux guide, according to an example embodiment. Regarding the first section 400 of the sensing element 314, the flux guide 312, and the flux guide reset mechanism, Figure 9 The configuration is similar to Figure 8A .However, Figure 9 The second section 402 of the flux guiding mechanism is different Figure 8A The second section 402 of the flux guiding mechanism. In this respect, for example, Figure 9 The flux guide mechanism includes an additional second coil segment 324A in the outer region 410, while Figure 8A The flux guide mechanism does not include these additional second coil segments 324A in the outer region 410. Furthermore, in Figure 9In this configuration, the flux guide reset mechanism is configured to energize the second coil 324 (i.e., at least the second coil segment 324A of both the inner region 408 and the outer region 410) and the first coil 322 (i.e., at least the first coil segment 322B of both the inner region 408 and the outer region 410) during the flux guide reset operation. Furthermore, in Figure 9 In the example shown, the flux guide reset mechanism is configured to select the activation of the second coil 324 such that during a sensing element reset operation, only the second coil segment 324A in the inner region is activated, while the second coil segment 324A in the outer region 410 is not activated. The advantage of this configuration is that the additional second coil segment 324A in the outer region 410 is configured to enhance and increase the total magnetic field at the end portion of the flux guide during the flux guide reset operation.

[0088] As discussed herein, the embodiments include numerous advantageous features and benefits. For example, embodiments are configured to apply a more uniform magnetic field to the elongated flux guide 312, thereby facilitating faster and more reliable magnetization switching. These embodiments are configured to provide this relatively uniform overall magnetic field while using lower operating currents to drive each coil of the flux guide reset mechanism. Additionally, there is an embodiment that provides a simplified coil layout by simultaneously optimizing the coil arrangement and current values ​​of the first coil 322 and the second coil 324 (and not the third coil 326).

[0089] These embodiments enable longer battery life in mobile devices such as smartphones, smartwatches, tablets, etc. Due to lower current wiring requirements and reduced external constraints, these embodiments also provide significant improvements in the printed circuit board (PCB) design of these mobile devices. Each embodiment reduces the voltage and power budget for flux conductor reset operations by optimizing a topology comprising at least two coils to provide a relatively uniform magnetic field distribution across the entire length of flux conductor 312, while also optimizing the current driving each of these coils to take advantage of this topological advantage.

[0090] As described above, the Z-sensor 202 includes an out-of-plane (Z-axis) tunneling magnetoresistive (TMR) magnetic field sensor that provides a stable output and minimizes the power required to operate the Z-sensor 202. The Z-sensor 202 includes at least a first coil 322 configured as a flux guide reset coil 208 and a second coil 324 configured as a sensing element reset coil 210. Additionally, the Z-sensor 202 is further configured to include a third coil 326 configured as a reset auxiliary coil 212. A combination of the first coil segments 322A / 322B and the second coil segment 324A, or a combination of the first coil segments 322A / 322B, the second coil segment 324A, and the third coil segment 326A, is activated to perform a flux guide reset operation, thereby enabling more accurate readout of the out-of-plane magnetic field while reducing the power required to operate the Z-sensor 202. Advantageously, these coil configurations are optimized without degrading the performance of the Z-sensor. Furthermore, as described above, by utilizing a custom UTM layer including copper as the first coil segment 322B, some of these embodiments help to achieve a more uniform field with lower current requirements for flux guide reset operations, thereby providing ultra-low resistance and close proximity to flux guide 312, so that the coupling field from a given voltage source is optimized.

[0091] In other words, the above description is intended to be illustrative rather than restrictive, and is provided in the context of a particular application and its requirements. Those skilled in the art will understand from the foregoing description that the invention can be implemented in various forms, and various embodiments can be implemented individually or in combination. Therefore, although embodiments of the invention have been described in conjunction with specific examples, the general principles defined herein can be applied to other embodiments and applications without departing from the spirit and scope of the described embodiments, and the true scope of the embodiments and / or methods of the invention is not limited to the shown and described embodiments, as various modifications will become apparent to those skilled in the art upon study of the drawings, specification, and appended claims. For example, components and functions may be separated or combined in ways different from the various described embodiments, and may be described using different terms. These and other variations, modifications, additions, and improvements may fall within the scope of this disclosure as defined in the appended claims.

Claims

1. A sensor structure, comprising: Sensing element; A flux guide is configured to guide magnetic flux in a plane for detection by the sensing element; A flux guide reset mechanism configured to set the flux guide to a predetermined magnetic orientation during a flux guide reset operation, the flux guide reset mechanism comprising: (i) a first coil configured to generate a first magnetic field, the first coil including a first coil segment; and (ii) a second coil configured to generate a second magnetic field, the second coil including a second coil segment. in, The flux guide is disposed between the first coil and the second coil; and The first coil is configured to have the same spacing as the sensing element and the same spacing as the second coil, such that the first magnetic field distribution of the first magnetic field and the second magnetic field distribution of the second magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

2. The sensor structure according to claim 1, wherein, The first coil segment and the second coil segment are configured such that a set of troughs in the first magnetic field distribution overlaps and combines with a set of peaks in the second magnetic field distribution.

3. The sensor structure according to claim 2, wherein: The first coil comprises copper; and The second coil comprises copper.

4. The sensor structure according to claim 3, wherein: The flux guide includes an internal region and an external region; The inner region corresponds to the portion of the flux guide that overlaps with the sensing element; The outer region includes the edge of the flux guide; The second coil segment overlaps with both the inner and outer regions; and The second coil segment is selectively controlled to (a) be energized during the flux guide reset operation to increase the total magnetic field at the edge of the flux guide, and (b) not be energized during the sensing element reset operation.

5. The sensor structure according to claim 3, further comprising: A sensing element reset circuit, configured to perform a reset operation on the sensing element, the sensing element reset circuit including a second coil. The second coil segment overlaps with the corresponding sensing element.

6. The sensor structure according to claim 1, wherein: The flux guide reset mechanism also includes a third coil; The third coil is configured to generate a third magnetic field; The third coil includes a third coil segment; The second coil segment and the third coil segment are disposed within the dielectric layer; and The first coil segment and the third coil segment are arranged relative to each other such that the first magnetic field distribution of the first magnetic field and the third magnetic field distribution of the third magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

7. The sensor structure according to claim 1, further comprising: A sensing element reset circuit, configured to perform a reset operation on the sensing element, the sensing element reset circuit including the second coil. The second coil segment overlaps with the corresponding sensing element.

8. A sensor structure, comprising: Sensing element; A flux guide is used to guide magnetic flux in a plane for detection by the sensing element; and A flux guide reset mechanism for setting the flux guide to a predetermined magnetic orientation, the flux guide reset mechanism comprising: (i) a first coil configured to generate a first magnetic field, the first coil including a first coil segment overlapping the flux guide; (ii) a second coil configured to generate a second magnetic field, the second coil including a second coil segment overlapping the flux guide; and (iii) a third coil configured to generate a third magnetic field, the third coil including a third coil segment overlapping the flux guide. in, The flux guide has one side facing the first coil and another side facing the second and third coils. The number of second coil segments overlapping with the flux guide is less than the number of third coil segments overlapping with the flux guide. The first coil is configured to have the same spacing as the sensing element and the same spacing as the second coil, such that the first magnetic field distribution of the first magnetic field and the second magnetic field distribution of the second magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

9. The sensor structure according to claim 8, wherein: The flux guide includes an internal region and an external region; The inner region corresponds to the portion of the flux guide that overlaps with the sensing element; The internal region includes the central portion of the flux guide; The outer region includes the edge of the flux guide; The internal region overlaps with a layout in which the second coil segment intersects with a set of third coil segments within the dielectric layer; and The outer region overlaps with another layout in which another set of third coil segments are arranged adjacent to each other within the dielectric layer.

10. The sensor structure according to claim 8, wherein, The first coil segment and the third coil segment are arranged relative to each other such that the first magnetic field distribution of the first magnetic field and the third magnetic field distribution of the third magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

11. The sensor structure according to claim 8, wherein: The first coil comprises copper; The second coil comprises copper; and The third coil comprises copper.

12. The sensor structure according to claim 8, wherein: The first coil segment and the second coil segment are arranged relative to each other such that a set of troughs in the first magnetic field distribution coincides with a set of peaks in the second magnetic field distribution. and The first coil segment and the third coil segment are arranged relative to each other such that a set of peaks in the first magnetic field distribution coincides with a set of peaks in the third magnetic field distribution.

13. The sensor structure according to claim 8, further comprising: A sensing element reset circuit, configured to perform a reset operation on the sensing element, the sensing element reset circuit including a second coil. The second coil segment overlaps with the corresponding sensing element.

14. A sensor structure, comprising: Sensing element; A flux guide is used to guide magnetic flux in a plane for detection by the sensing element; and A flux guide reset mechanism for setting the flux guide to a predetermined magnetic orientation, the flux guide reset mechanism comprising: (i) a first coil configured to generate a first magnetic field, the first coil including a first coil segment overlapping the flux guide; (ii) a second coil configured to generate a second magnetic field, the second coil including a second coil segment overlapping the flux guide; and (iii) a third coil configured to generate a third magnetic field, the third coil including a third coil segment overlapping the flux guide. in, The flux guide has one side facing the first coil and another side facing the second and third coils; and The first coil is configured to have the same spacing as the sensing element and the same spacing as the third coil, such that the first magnetic field distribution of the first magnetic field and the third magnetic field distribution of the third magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

15. The sensor structure according to claim 14, further comprising: A sensing element reset circuit, configured to perform a reset operation on the sensing element, the sensing element reset circuit including a second coil. The second coil segment overlaps with the corresponding sensing element.

16. The sensor structure according to claim 14, wherein: The flux guide includes an internal region and an external region; The inner region corresponds to the portion where the flux guide overlaps with the sensing element; The internal region includes the central portion of the flux guide; The outer region includes the edge of the flux guide; The internal region overlaps with a layout in which the second coil segment and a set of third coil segments are interleaved in an alternating pattern within the dielectric layer; and The outer region overlaps with another layout in which another set of third coil segments are arranged adjacent to each other within the dielectric layer.

17. The sensor structure according to claim 16, wherein, The third coil is configured to provide a peak value of magnetic flux density within the layout, which is smaller than another peak value of magnetic flux density within the other layout, to stabilize the magnetic flux density along the dimensions of the flux guide.

18. The sensor structure according to claim 14, wherein, The first coil segment and the second coil segment are configured relative to each other such that the first magnetic field distribution of the first magnetic field and the second magnetic field distribution of the second magnetic field are coherent with respect to at least a portion of the flux guide that overlaps with the sensing element.

19. The sensor structure according to claim 14, wherein: The first coil comprises copper; The second coil comprises copper; and The third coil comprises copper.

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