MIM magnet

Abstract

To provide a magnet for an electronic device.SOLUTION: In an electronic device, a magnet 550 can be formed as a unitary structure using metal injection molding. The magnet can be referred to as a neodymium magnet, i.e., so as to be formed from neodymium, iron, and boron. The magnet includes multiple easy axis generating polars 590, 592, 594, where the multiple easy axes are not parallel.SELECTED DRAWING: Figure 5B

Description

[Technical field]

[0001] Related Applications This application claims the benefit of U.S. Provisional Application No. 63 / 540,775, filed September 27, 2023, directed to "MIM Magnets," and U.S. Non-Provisional Application No. 18 / 896,214, filed September 25, 2024, directed to "MIM Magnets," which are hereby incorporated by reference in their entireties for all purposes. [Background technology]

[0002] The number of different types of electronic devices available on the market has increased enormously over the past few years, and the rate of adoption of new electronic devices shows no signs of slowing. Electronic devices such as tablet computers, laptop computers, all-in-one computers, desktop computers, smartphones, storage devices, wearable computing devices, portable media players, portable computing devices, navigation systems, monitors, audio devices, remotes, adapters, and other devices have become ubiquitous.

[0003] These electronic devices often contain magnets for a variety of reasons. Magnets can be used to attach two electronic devices together. Magnets can be used to attach an electronic device to an accessory. Magnets can be used to secure one part of an electronic device to another part of an electronic device.

[0004] More specific examples may include magnets that can secure audio devices within a case for charging. Other magnets can secure a case in a closed position. Magnets can be used on smartphones to attach and align wallets, battery packs, chargers, camera adapters, and other accessories. Magnets can be used to attach tablet computers to keyboards and other input devices.

[0005] However, these magnets can consume space within their electronic devices, and this use of space can require an increase in the size of the electronic device to house the magnets, a decrease in the functionality of the electronic device, or both.

[0006] Traditional magnet manufacturing can also result in the generation of virgin resources. For example, excess material may be cut away to produce magnets with a particular shape or form factor. These resources can be recycled or reused, but additional resources are required to do so.

[0007] Therefore, what is needed are magnets that are stronger, smaller, or both, and that are easily manufactured, as well as methods and apparatus that allow for the manufacture of magnets with reduced amounts of resources. Summary of the Invention

[0008] Thus, embodiments of the present invention can provide magnets that are stronger, smaller, or both, and that are easily manufactured, as well as methods and apparatus that enable the manufacture of magnets with reduced amounts of resources.

[0009] Exemplary embodiments of the present invention can provide a single magnet with a stronger magnetic field compared to a combination of magnets. The magnet can be formed as a single piece using metal injection molding or other processes. The magnet can be a neodymium magnet. That is, the magnet can be formed from neodymium, iron, and boron (NdFeB or NIB). In these and other embodiments of the present invention, other materials can be used, such as rare earth materials. Samarium-cobalt, manganese-bismuth, or other materials can be used. Ferrite materials can also be used.

[0010] Conventional magnets for electronic devices can be formed from several magnets attached to each other. Each of the individual magnets can include an easy axis formed in one direction. The combination of magnets can be placed proximally and fixed together, for example, using epoxy or other adhesives, holders, magnetic shields, or other structures. However, this can be inefficient and result in a bulky magnetic structure. Therefore, embodiments of the present invention can provide a unitary magnet that can include an easy axis positionable in three dimensions. Using such a unitary magnet can be more efficient. This efficiency can reduce the size of the magnet required, thereby saving resources. This can reduce the volume required for the magnet in the electronic device, can provide a stronger magnetic field, or a combination of these. This efficiency can also reduce excess or undesirable magnetic flux around the magnet and electronic device, thereby providing some protection for magnetically stored information, such as information on a credit card.

[0011] These and other embodiments of the present invention can provide magnets that are easily manufactured. For example, the magnets can be formed by metal injection molding or other molding processes. Multiple magnets can be used to force multiple polar orientations in the magnet while it is being formed. That is, multiple magnets can be placed around the molding while it is being formed. The multiple magnets can be permanent magnets, pole pieces, electromagnets, or combinations of these and other magnetic structures. Multiple magnets can pin the magnetic domains on the outer surface of the particle in different directions in the same magnet, such that the easy axis of the magnet has a curvature. This allows a single magnet to mimic several magnets placed close to each other.

[0012] Using a metal injection molding process can conserve resources required to form magnets for electronic devices. Traditional magnets can be formed by starting with a block of magnetic material and then removing excess magnetic material until a magnet with a desired form factor remains. The excess material can be recaptured, but the recaptured material requires further processing before it can be reused, and this further processing can require additional resources. Thus, these and other embodiments of the present invention can utilize metal injection or other molding when forming the magnets. Enough magnetic material is used for the actual magnet, as well as smaller excess parts such as gate marks and parting lines, thereby conserving resources. The smaller excess parts such as gate marks and parting lines can be trimmed from the finished magnet and easily reused in the manufacture of additional magnets with no or minimal further processing, which can further conserve resources.

[0013] These and other embodiments of the invention can provide a variety of magnet types. For example, an embodiment of the invention can provide magnets with shapes that may not be achievable by conventional methods. An embodiment of the invention can provide a unitary magnet with adjacent surfaces that meet to form an angle or an acute or obtuse angle. This can be particularly useful in mounting magnets in small spaces within small electronic devices such as earbuds or other electronic devices.

[0014] An embodiment of the present invention may provide a magnet that replaces the plurality of magnets. The replaced plurality of magnets may include a curved surface. An easy axis direction of each of the plurality of magnets may be perpendicular to the curved surface. An embodiment of the present invention may provide a unitary magnet having an easy axis direction that forms at least about a 180° rotation in the magnet.

[0015] An embodiment of the present invention can provide a magnet with a first polarity on a first side and a second polarity on a second side to replace a magnet with a center that has no magnetic polarity. An embodiment of the present invention can provide a unitary magnet with a first easy axis direction in a first direction on the first side and a second easy axis direction in a second direction on the second side. The center of the unitary magnet can further have a third easy axis direction with a polarity pointing in a third direction, the third direction being from the second side to the first side. The first easy axis direction and the second easy axis direction can converge at one of an acute angle or an obtuse angle. The third easy axis direction in the center of the magnet can allow the unitary magnet to be more efficient and therefore have a stronger magnetic field, a smaller size, or a combination thereof. These different easy axis directions can provide polarities that can be non-parallel and non-anti-parallel.

[0016] One embodiment of the present invention may provide a magnet to replace the magnet array. The unitary magnet may include an array of sections with different easy axes, each section providing a first polarity or a second polarity facing a surface of the electronic device, each row in the array comprising a section providing the first polarity and a section having the second polarity facing the surface, and each column in the array comprising a section having the first polarity and a section having the second polarity facing the surface.

[0017] An embodiment of the present invention can mimic (or implement the functionality of) a Halbach array using a single magnet. These embodiments can provide a single magnet where the magnetic field strength on a first side of the magnet is stronger than the magnetic field on a second side of the magnet.

[0018] These and other embodiments of the present invention can provide magnets of other shapes. For example, embodiments can provide a conventional bar magnet. Commercially available bar magnets may not be available in the exact size required, and therefore such bar magnets can be manufactured more efficiently since material still needs to be removed to form the bar magnet. Also, embodiments can provide stronger magnets than are commercially available. Embodiments of the present invention can be used to form other shapes, such as plus sign or "X" shaped magnets, ring magnets, "S" shaped magnets, horseshoe magnets, or other shaped magnets.

[0019] Embodiments of the present invention can provide a unitary magnet with different easy axis directions at different locations. Also, embodiments can provide a unitary magnet with one polarity direction throughout the magnet. Commercially available magnets may not be available in the exact size required, and therefore such magnets can be made more efficiently since material still needs to be removed to form a magnet with one polarity direction. Also, embodiments can provide stronger magnets than are commercially available.

[0020] Various embodiments of the present invention may incorporate one or more of these and other features described herein. A better understanding of the nature and advantages of the present invention can be obtained by reference to the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0021] [Figure 1A] 1 shows a magnet according to one embodiment of the present invention. [Figure 1B] 1 shows a magnet according to one embodiment of the present invention.

[0022] [Figure 2A] 1 shows a group of magnets. [Figure 2B] 2B shows a single magnet that can replace the group of magnets in FIG. 2A according to one embodiment of the present invention.

[0023] [Diagram 3] 1 shows a single magnet according to one embodiment of the present invention.

[0024] [Figure 4A] 1 shows a group of magnets. [Figure 4B] 4B illustrates a single magnet that can replace the group of magnets in FIG. 4A according to one embodiment of the present invention.

[0025] [Figure 5A] A magnet is shown. [Figure 5B] 5B shows a unitary magnet according to one embodiment of the present invention that can improve upon the magnet of FIG. 5A.

[0026] [Figure 6A] 1 shows an electronic device comprising a group of magnets; [Figure 6B] 6B shows a number of individual magnets that can replace the group of magnets in FIG. 6A.

[0027] [Figure 7A] 1 shows a Halbach array formed from several magnets. [Figure 7B] 7B shows a single magnet implemented to mimic a Halbach array that can replace the magnet in FIG. 7A.

[0028] [Figure 8] FIG. 1 illustrates a molding system that can be used to manufacture a single-piece molded magnet according to one embodiment of the present invention.

[0029] [Figure 9] FIG. 1 illustrates the processes involved in manufacturing a magnet according to one embodiment of the present invention.

[0030] [Figure 10] 1 illustrates a method of manufacturing a magnet according to an embodiment of the present invention.

[0031] [Figure 11] 13A-13C show coil configurations that may be used during the manufacture of magnets according to embodiments of the present invention.

[0032] [Figure 12] 13A-13C show coil configurations that may be used during the manufacture of magnets according to embodiments of the present invention.

[0033] [Figure 13] 1A-1C show coil configurations that can be used in manufacturing a magnet according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] 1A and 1B show a unitary magnet according to an embodiment of the present invention. Magnet 100 can include several curved, acute, obtuse, tapered, and other non-orthogonal surfaces and intersections of surfaces. For example, magnet 100 can include curved surface 140. Magnet 100 can include surfaces 110 and 150 that can meet to form an acute angle. Surfaces 120 and 130 can meet to form an obtuse angle. Magnet 100 can also include surfaces 110, 120, and 150 that can meet at a tapered point 112. These various contours can be provided using metal injection molding or other techniques provided by embodiments of the present invention. These contours would be extremely difficult or impossible to machine from a block.

[0035] The easy axis (not shown) may be in different directions at different portions of magnet 100. As a result, the polarity direction of magnet 100 may be non-linear. For example, the polarity direction may enter surface 130 and exit surface 160, which may be on non-opposite sides. The polarity direction may be orthogonal or perpendicular to surface 140 across its curvature. That is, the easy axes at different locations of magnet 100 may be non-parallel. In these and other embodiments of the invention, a magnet may have one polarity direction. For example, magnet 100 may be formed to have one polarity direction.

[0036] The unitary magnet 100 may be formed by metal injection molding or other molding processes. By using metal injection molding or other molding processes, the unitary magnet 100 may be provided with shapes, features, and non-linear or non-parallel magnetic field characteristics that may be impossible or difficult to manufacture, especially in large quantities. The unitary magnet 100 may be referred to as a neodymium magnet. That is, the magnet 100 may be formed from neodymium, iron, and boron (NdFeB). In these and other embodiments of the invention, other materials may be used, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and may be combined with a binder to create a feedstock material. The feedstock material may be heated and injected into a mold. A magnetic field may be applied to the mold to force the non-parallel easy axes. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in an electronic device. Portions of the molded magnets, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may contain voids or open areas within its volume. For example, the unitary magnet 100 may contain 2, 3, 4, or other percent voids.

[0037] A magnetic field can be applied to magnet 100 during the molding process to force a non-linear polarity orientation of magnet 100. That is, a magnetic field can be applied to magnet 100 during the molding process to reinforce the non-linear easy axis of magnet 100. These magnets can be permanent magnets, magnetic elements such as pole pieces, electromagnets, or other structures capable of transmitting or generating a magnetic field, or combinations thereof. An example is shown in FIG. 8. Examples of other magnets that can have non-linear or non-parallel easy axes are shown in the following figures.

[0038] FIG. 2A shows a group of magnets and FIG. 2B shows a single magnet according to an embodiment of the present invention that can replace the group of magnets in FIG. 2A. FIG. 2A shows a group of magnets 200 including magnets including magnet 210, magnet 212, magnet 214, and magnet 216. Magnet 210, magnet 212, magnet 214, and magnet 216 can be held together and supported by base 230 and base 232. Magnet 210, magnet 212, magnet 214, magnet 216, base 230, and base 232 can be held together using an adhesive or other material. Magnet 210 can include an easy axis direction 220 that is approximately perpendicular to surface 211. Magnet 212 can include an easy axis direction 222 that is approximately perpendicular to surface 213. Magnet 214 can include an easy axis direction 224 that is approximately perpendicular to surface 215. Magnet 216 can include an easy axis direction 226 that is approximately perpendicular to surface 217.

[0039] Magnets 210 and 212 can have poles of a first polarity that can be arranged to be at least approximately perpendicular to surfaces 211 and 213, respectively. Magnets 214 and 216 can have poles of a second polarity that can be arranged to be at least approximately perpendicular to surfaces 215 and 217, respectively. The easy axes of each of magnets 210, 212, 214, and 216 can be oriented in the directions of their easy axis directions, easy axis direction 220, easy axis direction 222, easy axis direction 224, and easy axis direction 226.

[0040] Figure 2B illustrates a unitary magnet according to an embodiment of the present invention that can replace the group of magnets in Figure 2A. The unitary magnet 240 can include a curved surface 242 having a first portion 244 and a second portion 246. The easy axis direction 250 can be approximately perpendicular to the portion 246 of the surface 242, which can be approximately perpendicular to the portion 244 of the surface 242. This results in the portion 246 of the surface 242 having a first polarity and the portion 244 of the surface 242 having a second polarity.

[0041] The magnet 240 can have poles of a first polarity that can be arranged to be at least approximately perpendicular to the portion 244 of the surface 242. The magnet 240 can have poles of a second polarity that can be arranged to be at least approximately perpendicular to the portion 246 of the surface 242. The polarity of the magnet 240 can follow a curve that can be oriented in the direction of the easy axis direction 250.

[0042] The magnet 240 can be a unitary magnet. That is, the magnet 240 can be formed as a single piece. Thus, the base 230 and base 232 shown in FIG. 2A are not required, but a base (not shown) can be used to secure the magnet 240 in position within the electronic device. Also, because the magnet 240 is a unitary magnet, there is no need to attach parts of the magnet 240 to each other using adhesives or other materials. This can reduce the number of parts required to manufacture the electronic device, simplifying its assembly, saving resources, and reducing rework. This can also result in a smaller unitary magnet 240, which saves space compared to the group of magnets 200. This space savings can allow an electronic device including the unitary magnet 240 to be smaller, can allow the electronic device to include more functionality, or both. Although the easy axis directions 250 are shown to converge, the unitary magnet 240 can include diverging easy axis directions.

[0043] The magnet 240 may be formed by metal injection molding or other molding processes. The magnet 240 may be referred to as a neodymium magnet. That is, the magnet 240 may be formed from neodymium, iron, and boron. Other materials, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials, may be used in these and other embodiments of the present invention. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and combined with a binder to create a feedstock. The feedstock may be heated and injected into a mold. A magnetic field may be applied to the mold to force non-parallel easy axes. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in an electronic device. Portions of the molded magnet, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may include voids or open areas within its volume. For example, the unitary magnet 240 may include 2, 3, 4, or other percent air gaps.

[0044] A magnetic field can be applied to the magnet 240 during the molding process to force a nonlinear polar orientation of the magnet 240. That is, a magnetic field can be applied to the magnet 240 during the molding process to reinforce the nonlinear easy axis of the magnet 240. The magnetic field can be generated using permanent magnets, pole pieces, electromagnets, or a combination of these and other magnetic structures. An example is shown in FIG. 8. In this example, the easy axis direction 250 can be implemented in various ways during the manufacturing process. For example, an electromagnet having a winding around a U-shaped core that follows the contour of the desired easy axis direction 250 can be placed near the front and back sides of the magnet 240 (the front side is seen in FIG. 2B). Current flowing through the winding can curvilinearly align the magnetic domains in the magnet 240 to generate the desired easy axis direction 250.

[0045] FIG. 3 shows a unitary magnet according to an embodiment of the present invention. The magnet 300 can have a first side 310 along the outer circumference and a second side 320 along the inner circumference. The magnet 300 can have a shape that is an arc of a circle. In this example, the magnet 300 can have a semicircular shape, but in other examples, the magnet 300 can be less than half a circle or more than half a circle, for example, the magnet 300 can be a full circle instead. The magnet 300 can be one of two magnets that can be combined to form a full circle. A pair of semicircular magnets can be used on each of two compatible electronic devices to provide an attachment mechanism between the electronic devices. The easy axis direction can be different for each pair of semicircular magnets. An example is shown in the following figure.

[0046] FIG 4A shows a group of magnets and FIG 4B shows a single magnet according to an embodiment of the present invention that can replace the group of magnets in FIG 4A. FIG 4A shows a group of magnets 400 including magnet 430, magnet 432, magnet 434, and magnet 436. Magnet 430, magnet 432, magnet 434, and magnet 436 can be held together using a base, shield, or other structure, adhesive such as epoxy, or other structure, material, or combination of structures or materials. Magnet 432, magnet 434, and magnet 436 can have an outer edge 410 along a perimeter and an inner edge 420 along an inner parameter.

[0047] Magnet 430 can have an easy axis direction 440. Easy axis directions 440 can be parallel to each other and can extend from outer edge 410 to inner edge 420, as can other easy axis directions shown in this example. Magnet 432 can have an easy axis direction 442 that can also be parallel to each other. Similarly, magnet 434 can have parallel easy axis directions 444, and magnet 436 can have parallel easy axis directions 446. Although parallel easy axis directions can tend to converge to the center of the circle defined by the arc made by group of magnets 400, actual convergence is not achievable since the easy axis directions are parallel to each other within each magnet. Thus, an embodiment of the present invention can provide a single magnet to replace group of magnets 400. The single magnet can have an easy axis direction that converges to the center point of the circle defined by the arc made by the single magnets. One example is shown in FIG. 4B.

[0048] FIG. 4B illustrates a unitary magnet according to an embodiment of the present invention that can replace the group of magnets in FIG. 4A. Because magnet 450 is a unitary magnet, magnet 450 does not need to be held together using a base, shield, epoxy, or other material, thereby simplifying the assembly process for an electronic device that houses unitary magnet 450. Some of these or other materials may be used to secure unitary magnet 450 in place within an electronic device. Unitary magnet 450 may be more efficient, allowing unitary magnet 450 to be smaller. This reduced size may save space within the electronic device, allow additional functionality to be included within the electronic device, or a combination of both.

[0049] The unitary magnet 450 can have an outer edge 460 along the perimeter and an inner edge 470 along the inner parameter. An easy axis direction 448 can extend in a direction from the outer edge 460 to the inner edge 470. The easy axis direction 448 can converge to a center 490 of a circle defined by the arc shape of the unitary magnet 450. This can help increase the force of attraction between the magnet 450 in the first electronic device and a magnet such as the unitary magnet 550 (shown in FIG. 5B). The unitary magnet 450 can have a polar direction that is truly radial rather than polygonal, which can increase electromagnetic efficiency.

[0050] The unitary magnet 450 can have poles of a first polarity that can be disposed along an outer edge 460 of the magnet 450. The unitary magnet 450 can have poles of a second polarity that can be disposed along an inner edge 470 of the magnet 450. The magnet 450 can generate magnetic field lines that can follow the direction of the easy axis direction 448.

[0051] The unitary magnet 450 may be formed by metal injection molding or other molding process. The magnet 450 may be referred to as a neodymium magnet. That is, the magnet 450 may be formed from neodymium, iron, and boron. Other materials may be used in these and other embodiments of the invention, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and combined with a binder to create a feedstock. The feedstock may be heated and injected into a mold. A magnetic field may be applied to the mold to force non-parallel easy axes. An example is shown in FIG. 8. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in electronic devices. Portions of the molded magnet, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may include voids or open areas within its volume. For example, the unitary magnet 450 may include 2, 3, 4, or other percent air gaps.

[0052] A magnetic field can be applied to the magnet 450 during the molding process to force a nonlinear polarity orientation of the magnet 450. That is, a magnetic field can be applied to the magnet 450 during the molding process to reinforce the nonlinear easy axis of the unitary magnet 450. The magnetic field can be generated using permanent magnets, pole pieces, electromagnets, or a combination of these and other magnetic structures. In this example, the easy axis direction 448 can be implemented in various ways during the manufacturing process. For example, a first polarity of the magnet can be positioned at the center 490 of the circle defined by the arc of the magnet 450. A second polarity of the magnet can be positioned along the outer edge 460 of the magnet 450. This can generate a magnetic field that can align the particles of the magnet 450 during molding such that the finished magnet 450 has an easy axis direction 448.

[0053] FIG. 5A shows a magnet and FIG. 5B shows a unitary magnet according to an embodiment of the present invention that can improve upon the magnet of FIG. 5A. FIG. 5A shows a magnet 500. The magnet 500 can be supported by a shield 505 or other structure. The magnet 500 can have a first end 510 and a second end 520. The magnet 500 can have a non-magnetized portion 530 between the first end 510 and the second end 520. The first end 510 can have an easy axis direction for generating a polarity 540, and the second end 520 can have an easy axis direction for generating a polarity 542. The polarity 540 and the polarity 542 can be parallel. That is, the easy axis generated polarity 540 and the easy axis generated polarity 542 can be non-converging.

[0054] The easy axis of the first end 510 can be in the same direction as the easy axis of the second end 520. The polarity directions of the first end 510 and the second end 520 can be in opposite directions. The first end 510 can have a pole on a surface 512 with a first polarity, and the second end 520 can have a pole on a surface 522 with a second polarity.

[0055] A portion 530 of magnet 500 is not magnetized, or at least not strongly magnetized. For example, a first end 510 of magnet 500 can be magnetized in a first direction and a second end 520 of magnet 500 can be magnetized in a second, opposite direction. Given the limitations of the magnetizer, portion 530 is not magnetized. A shield 505 can be used to complete the path of the magnetic flux of magnet 500.

[0056] More specifically, the magnet 500 may be one of a group of magnets forming a circular arc. This may be the same as or similar to the group of magnets 400 (shown in FIG. 4A). That is, the magnet 500 may have a top view that is the same as or similar to the magnet 400 (shown in FIG. A). A first circular magnet may be formed from the group of magnets 500 and placed in a first electronic device (not shown). A second electronic device (not shown) may include two magnets 450 (shown in FIG. 4B). Magnetic flux from a first end 510 of the magnet 500 may pass through the shield 505, thereby bypassing the non-magnetized portion 530, and may pass through a second end 520 of the magnet 500. The magnetic flux may pass from the outer edge 460 to the inner edge 470 of the single magnet 500 and back to the first end 510 of the magnet 450.

[0057] Thus, magnet 500 may have some limitations. Multiple magnets 500 are needed to form a semicircular arc. Also, non-magnetized portion 530 may reduce the effectiveness of magnet 500 and reduce the strength of the magnetic field of magnet 500. Due to the presence of non-magnetized portion 530, it may be necessary to use a shield with magnet 500 to generate a magnetic field sufficient to attach two electronic devices together. Thus, an embodiment of the present invention may provide a single magnet that does not include a non-magnetized portion so that each can form a semicircular magnet and no shield is required. An example is shown in the following figure.

[0058] FIG. 5B shows a unitary magnet according to an embodiment of the present invention that can improve upon the magnet of FIG. 5A. FIG. 5A shows a unitary magnet 500. The magnet 500 can be supported by a shield, a plastic housing, or other structure when assembled into an electronic device. The magnet 500 can have a first end 560 and a second end 570. The magnet 500 can have a transversely magnetized portion 580 between the first end 560 and the second end 570. The first end 560 can have an easy axis generated polarity 590 and the second end 570 can have an easy axis generated polarity 594. The portion 580 can have an easy axis generated polarity 592 that extends from the first end 560 to the second end 570. The easy axis generated polarity 590 and the easy axis generated polarity 592 can be non-parallel easy axis directions. That is, the easy axis generated polarity 540 and the easy axis generated polarity 542 can be converging easy axis directions.

[0059] The easy axis of the first end 560 can be in a different direction than the easy axis of the second end 570. The polar directions of the first end 560 and the second end 570 can be essentially opposite, but non-parallel, converging directions. The first end 560 can have poles on a surface 562 with a first polarity, and the second end 570 can have poles on a surface 572 with a second polarity.

[0060] Portion 580 of magnet 500 may be magnetized in contrast to portion 530 of magnet 500 (shown in FIG. 5A). For example, first end 560 of magnet 550 may be magnetized in a first direction and second end 570 of magnet 550 may be magnetized in a direction somewhat closer to a second, opposite direction. Portion 580 may be magnetized in a direction from first end 560 to second end 570. This may complete a path for the magnetic flux of magnet 550 without the need for a shield.

[0061] More specifically, the magnet 550 may be a single magnet that forms an arc, such as a semicircle, although the magnet 500 may outline more or less than half of a circle. It may be the same as or similar to the magnet 450 (shown in FIG. 4B). That is, the magnet 550 may have a top view that is the same as or similar to the magnet 450 (shown in FIG. 4B). A first circular magnet may be formed using two magnets 550 and placed in a first electronic device (not shown). A second electronic device (not shown) may include a circular magnet formed from two magnets 450 (shown in FIG. 4B). Magnetic flux from the first end 560 of the magnet 550 may pass through the portion 580 and through the second end 570 of the magnet 550 without the need for a shield. Magnetic flux may pass from the outer edge 460 of the single magnet 550 to the inner edge 470 and back to the first end 560 of the magnet 450. In this manner, the single magnets 450 and 550 can form a strong magnetic attraction between the first electronic device and the second electronic device.

[0062] The unitary magnet 550 may be formed by metal injection molding or other molding process. The magnet 550 may be referred to as a neodymium magnet. That is, the magnet 550 may be formed from neodymium, iron, and boron. Other materials may be used in these and other embodiments of the invention, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and combined with a binder to produce a feedstock. The feedstock may be heated and injected into a mold. A magnetic field may be applied to the mold to force non-parallel easy axes. An example is shown in FIG. 8. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in electronic devices. Portions of the molded magnet, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may include voids or open areas within its volume. For example, the unitary magnet 550 may include 2, 3, 4, or other percent air gaps.

[0063] A magnetic field can be applied to the magnet 550 during the molding process to force a nonlinear polarity direction of the magnet 550. That is, a magnetic field can be applied to the magnet 550 during the molding process to reinforce the nonlinear easy axis of the unitary magnet 550. The magnetic field can be generated using permanent magnets, pole pieces, electromagnets, or a combination of these and other magnetic structures. In this example, the easy axis direction generating polarities 590, 592, and 594 can be implemented in various ways during the manufacturing process. For example, an electromagnet can be placed over the magnet 550, and the electromagnet can be curved to follow the semicircular contour of the magnet 550. The resulting magnetic field can be around the magnet 550 which can align the particles of the magnet 550 during molding so that the finished magnet 550 has the easy axis direction generating polarities 590, 592, and 594.

[0064] FIG. 6A shows an electronic device with a group of magnets, and FIG. 6B shows a group of magnets that can replace the group of magnets in FIG. 6A. FIG. 6A shows a magnet array 610 with some magnets 620 with a first pole facing the bottom side of the electronic device 600 (as shown) and some magnets 630 with a second pole facing the bottom side of the electronic device 600. Each row in the magnet array 610 can include one or more magnets with a first pole and one or more magnets with a second pole facing the bottom side of the electronic device 600. Each column in the magnet array 610 can include one or more magnets with a first pole and one or more magnets with a second pole facing the bottom side of the electronic device 600. The magnet array 610 can be used to attach a second electronic device (not shown) to the electronic device 600. For example, the second electronic device may include a group of magnets with opposite poles that attract the magnet array 610, thereby attaching the electronic device 600 to the second electronic device.

[0065] The magnet array 610 can be assembled by grouping nine magnets together either by hand or by machine. Either way, this process is time consuming and can result in yield loss. Errors can result in rework being required and consuming resources. Thus, an embodiment of the present invention can replace the nine magnets used to form the magnet array 610 with a single, standalone magnet. An example is shown in the following figure.

[0066] FIG. 6B shows a number of unitary magnets that can replace the group of magnets in FIG. 6A. In this example, a unitary magnet 650 can be used in place of the magnet array 610 (shown in FIG. 6A). The unitary magnet can have several sections 660 with a first pole and several sections 670 with a second pole facing the bottom surface (as shown) of the electronic device 640. Each row of sections in the magnet 650 can include one or more sections 660 with a first pole and one or more sections 670 with a second pole facing the bottom of the electronic device 640. Each column in the magnet array 610 can include one or more sections 660 with a first pole and one or more sections 670 with a second pole facing the bottom of the electronic device 640. The unitary magnet 650 can be used to attach a second electronic device (not shown) to the electronic device 640. For example, the second electronic device may include a group of magnets with opposite poles that attract the single magnet 650, thereby attaching the electronic device 640 to the second electronic device.

[0067] The use of single magnets 650 can simplify the manufacture of electronic device 640. For example, groups of magnets do not need to be aligned and fixed to one another as in magnet array 610. Also, single magnets 650 can be smaller, thereby saving space within electronic device 640 and allowing electronic device 640 to be smaller, contain more functionality, or both. This can reduce assembly time, improve yields, reduce rework, and conserve resources.

[0068] The unitary magnet 650 may be formed by metal injection molding or other molding process. The magnet 650 may be referred to as a neodymium magnet. That is, the magnet 650 may be formed from neodymium, iron, and boron. Other materials may be used in these and other embodiments of the invention, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and may be combined with a binder to produce a feedstock. The feedstock may be heated and injected into a mold. A magnetic field may be applied to the mold to force non-parallel easy axes. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in an electronic device. Portions of the molded magnet, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may include voids or open areas within its volume. For example, the unitary magnet 650 may include 2, 3, 4, or other percent air gaps.

[0069] A magnetic field can be applied to the magnet 650 during the molding process to force different polarity orientations on the sections of the magnet 650. An example is shown in FIG. 8. That is, a magnetic field can be applied to the magnet 650 during the molding process to reinforce different polarities of the unitary magnet 650. The magnetic field can be generated using permanent magnets, pole pieces, electromagnets, or a combination of these and other magnetic structures. In this example, the poles for sections 660 and 670 can be reinforced in various ways during the manufacturing process. For example, multiple magnets can be placed above and below the magnet 650 (where below is the orientation of FIG. 6B). The magnets below the magnet 650 can have the same pattern as shown for the magnet 650 facing the bottom side of the magnet 650 (not shown). The magnets above the magnet 650 can have polarities of the opposite pattern facing the top side of the magnet 650 (shown here). The resulting magnetic field can align the particles of the magnet 650 during molding so that the finished magnet 650 has sections 660 and 670 with the desired polarities.

[0070] FIG. 7A shows a Halbach array formed from several magnets, and FIG. 7B shows a single magnet implemented to mimic a Halbach array that can replace the magnet of FIG. 7A. FIG. 7A shows a Halbach array 700 formed from several magnets, including magnet 710, magnet 712, magnet 714, magnet 716, and magnet 718. The magnets of the Halbach array 700 can be arranged such that their polarities generated by the easy axis directions rotate counterclockwise from left to right (as depicted). For example, magnet 710 can have an easy axis direction that generates a polarity 740 that extends horizontally to the right (as depicted). Magnet 712 can have an easy axis direction that generates a polarity 742 that is rotated 90° counterclockwise relative to the polarity 740 of magnet 710. Magnet 714 can have a polarity 744 that is rotated 90° counterclockwise relative to the polarity 742 of magnet 712. Similarly, magnet 716 can have a polarity 746 that is rotated 90 degrees counterclockwise relative to polarity 744 of magnet 714, and magnet 718 can have a polarity 748 that is rotated 90 degrees counterclockwise relative to polarity 746 of magnet 716.

[0071] The arrangement of the Halbach array 700 can produce an upper easy axis direction 720 that is stronger than a lower easy axis direction 730. That is, the magnetic field from the bottom of the Halbach array 700 can be re-routed to the top. This can effectively increase the magnetic field at the top of the Halbach array 700. Also, stray magnetic flux at the bottom of the Halbach array 700 can be reduced.

[0072] The Halbach array 700 can be difficult to manufacture. For example, the various magnets may need to be held in place relative to one another using a base or other substrate. This can be difficult because the magnets in the Halbach array 700 may strongly repel one another. The magnets can be held together using adhesives such as epoxy or other materials. Because the magnets in the Halbach array 700 repel one another, stronger adhesives may need to be used. The use of these materials can reduce the efficiency and field strength of the Halbach array 700. To compensate, the magnets can be made larger, but this can increase the space that the Halbach array 700 takes up in the electronic device and can increase the amount of resources consumed in their manufacture. Thus, embodiments of the present invention can replace the multiple magnets used to form the Halbach array 700 with a single, unitary magnet. One example is shown in the following figure.

[0073] FIG. 7B shows a single magnet implemented to mimic a Halbach array that can replace the magnet of FIG. 7A. The use of a single magnet 750 can eliminate or reduce the complications that arise due to magnet repulsion and the need for strong adhesives in manufacturing the Halbach array 700 (shown in FIG. 7A). The Halbach array 755 can be implemented as a single magnet 750. Note that the magnet 750 can be referred to as a Halbach array 755 here, even though it is implemented as a single magnet and not an array of magnets. The single magnet 750 can include several sections with different easy axes that result in different polarity directions. That is, each of the several sections can have a different orientation for their easy axis directions. The particles of the single magnet 750 can be arranged such that their polarity rotates counterclockwise from left to right. For example, a section 780 of the single magnet 750 can have a polarity 790 that extends horizontally to the right (as depicted). Section 782 can have a polarity 792 rotated 90 degrees counterclockwise upward relative to the polarity 790 of section 780. Section 784 can have a polarity 794 rotated 90 degrees counterclockwise relative to the polarity 792 of section 782. Similarly, section 786 can have a polarity 796 rotated 90 degrees counterclockwise relative to the polarity 794 of section 784, and section 788 can have a polarity 798 rotated 90 degrees counterclockwise relative to the polarity 796 of section 786.

[0074] The arrangement of sections in the single magnet 750 can generate a stronger top magnetic field 760 than the bottom magnetic field 770. That is, the magnetic field 770 from the bottom of the single magnet 750 can be redirected to the top. This effectively increases the magnetic field 760 at the top of the single magnet 750. It also reduces stray magnetic flux at the bottom of the single magnet 750.

[0075] The use of single magnets 750 in the Halbach array 755 can simplify the manufacture of electronic devices. For example, groups of magnets do not need to be aligned and fixed to one another as in the Halbach array 700 (shown in FIG. 7A). This can reduce assembly time, improve yield, reduce rework, and conserve resources. The single magnets 750 can be more efficient, thereby allowing the Halbach array 755 to be smaller than the Halbach array 700, which can allow electronic devices to be smaller, contain more functionality, or both.

[0076] The unitary magnet 750 may be formed by metal injection molding or other molding process. The unitary magnet 750 may be referred to as a neodymium magnet. That is, the magnet 750 may be formed from neodymium, iron, and boron. Other materials may be used in these and other embodiments of the invention, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used. Powdered neodymium, iron, and boron (NdFeB) may be formed by grinding crystalline NdFeB and combined with a binder to create a feedstock. The feedstock may be heated and injected into a mold. A magnetic field may be applied to the mold to force non-parallel easy axes. An example is shown in FIG. 8. The molded magnet may be debonded, i.e., the binder may be removed. The molded magnet may be sintered, and the result may be used in electronic devices. Portions of the molded magnet, such as gate marks and parting lines, may be removed before or after sintering and reused as feedstock. The molded magnet may include voids or open areas within its volume. For example, the unitary magnet 750 may include 2, 3, 4, or other percent air gaps.

[0077] A magnetic field can be applied to the magnet 750 during the molding process to force different polarity directions on sections of the magnet 750. That is, a magnetic field can be applied to the magnet 750 during the molding process to reinforce the rotational polarity of the unitary magnet 750. The magnetic field can be generated using permanent magnets, pole pieces, electromagnets, or a combination of these and other magnetic structures. In this example, the easy axis can be reinforced in various ways during the manufacturing process. For example, multiple magnets arranged as a Halbach array can be placed on the top and bottom of the unitary magnet 750 (where down is the direction to FIG. 6B). The magnets on the sides of the unitary magnet 750 can have the same pattern as shown for the unitary magnet 750. The resulting magnetic field can align the grains of the unitary magnet 750 during molding so that the finished unitary magnet 750 has the desired rotational polarity.

[0078] For example, the magnets may be formed by metal injection molding or other molding processes. Metal injection molding or other molding processes may be used to provide the unitary magnets with shapes, features, and non-linear or non-parallel magnetic field characteristics that may be impossible or difficult to manufacture, especially in large quantities. These and other unitary magnets may be neodymium magnets. These and other unitary magnets may be formed of neodymium, iron, and boron. Other materials may be used in these and other embodiments of the invention, such as rare earth materials, such as samarium-cobalt, manganese-bismuth, or other materials. Ferrite materials may also be used.

[0079] In these and other embodiments of the invention, powdered neodymium, iron, and boron can be combined with a binder to create a feedstock material. The feedstock material can be heated and injected into a mold. A magnetic field can be applied to the mold to force non-parallel easy axes. The molded magnet can be debonded, i.e., the binder can be removed. The molded magnet can be removed from the mold before debonding. The molded magnet can be sintered, and the result can be used in an electronic device. The molded magnet can also be removed from the mold before sintering. Portions of the molded magnet, such as gate marks and parting lines, can be removed before or after sintering and reused as feedstock material. The molded magnet can include voids or open areas within its volume. For example, the unitary magnet 100 can include 2, 3, 4, or other percent voids.

[0080] A magnetic field can be applied to the magnet during the molding process to force a nonlinear polarity orientation of the molded magnet. That is, a magnetic field can be applied to magnet 100 during the molding process to reinforce the nonlinear easy axis of magnet 100. These magnets can be permanent magnets, magnetic elements such as pole pieces, electromagnets, or other structures capable of transmitting or generating a magnetic field, or a combination thereof. An example of this process is shown in the following figure.

[0081] 8 illustrates a molding system that can be used to manufacture a unitarily molded magnet according to one embodiment of the present invention. The molding system 800 can include a mold 810 having a top 812 and a bottom 814. The top 812 and bottom 814 can form a cavity 816 and a gate 818. The coils 830 and 832 can be contained within the mold 810 or can be molded or disposed around the mold 810.

[0082] During manufacturing, a powder is created by grinding neodymium, iron, and boron (NdFeB), which may be crystalline. The powdered neodymium, iron, and boron may be combined with a binder to create a feedstock. The feedstock may be heated and injected through gate 818 into cavity 816 of mold 810 to form magnet 820. Current may be passed through either or both of coil 830 and coil 832 to create magnetic field 834. The magnetic fields of magnetic field 834 may be non-parallel. Magnetic field 834 may be present while magnet 820 is being formed. The easy axis of magnet 820 may follow the magnetic field lines of magnetic field 834. Magnetic field 834 may be generated by coil 830 and coil 832, or other coils, permanent magnets, magnets, magnetic elements such as pole pieces, electromagnets, or other structures capable of transmitting or generating a magnetic field, or combinations thereof.

[0083] After the magnet 820 is formed, the binder can be removed by a debinding process. The debinding process can leave voids in the magnet 820. These voids can be removed by sintering the magnet 820. Excess portions on the magnet 820, such as the gate portion 822 and the parting line (not shown) between the top 812 and bottom 814 of the mold 810, can be removed, for example, by trimming. In these and other embodiments of the invention, the magnet 820 can be removed from the mold 810 during the debinding and sintering processes. While the magnet 820 is in the mold 810, the magnetic field 834 can be generated by either or both of the coil 830 and the coil 832. Alternatively, the magnetic field 834 can be generated by a permanent magnet, a magnetic element such as a magnet, a pole piece, an electromagnet, or other structure capable of carrying or generating a magnetic field, or a combination thereof. The magnetic field 834 can be a constant or variable magnetic field during these processes.

[0084] In this example, a powdered neodymium, iron, and boron (NdFeB) mixture can be formed by grinding crystalline NdFeB permanent magnets and combined with a binder to create a feedstock for injection into the mold 810. In these and other embodiments of the invention, other materials can be used, such as rare earth materials. Samarium-cobalt, manganese-bismuth, or other materials can be used. Ferrite materials can also be used.

[0085] Mold 810 may be formed from a variety of materials that do not react with the feedstock used. For example, mold 810 may be formed from steel, stainless steel, cast iron, iron, or other materials. Either or both of coil 830 and coil 832 may be within mold 810, e.g., mold 810 may be formed or assembled around coil 830 and coil 832. Alternatively, either or both of coil 830 and coil 832 may be disposed around mold 810. Although two coils, coil 830 and coil 832, are shown in this example, molding system 800 may include one, three, four, five, or more than five coils. Also, while coil 830 and coil 832 are shown as being parallel, coil 830 and coil 832 may have other spatial relationships, e.g., they may be diagonal, orthogonal, offset, or may have other spatial relationships.

[0086] Coil 830 and coil 832 can share the same current or can have separate currents, which can have the same or different directions, durations, and magnitudes. Either or both of these currents can be constant or variable, i.e., their magnitudes can change over time. Either or both of these currents can be on for a duration that is at least a significant portion of the time required for the molding process. Either or both of these currents can be on for one or more short durations of relatively large magnitude, or a combination of such currents of longer and shorter durations can be used during the molding process. Coil 830 and coil 832 can be connected in series or parallel to a current source (not shown). Coil 830 and coil 832 can each be connected to a separate current source.

[0087] After the magnet 820 is molded, the binder can be removed and the magnet 820 can be sintered. One example is shown in the following figure.

[0088] FIG. 9 illustrates the processes involved in manufacturing a magnet according to an embodiment of the invention. During manufacturing, powder 910 can be made by grinding neodymium, iron, and boron (NdFeB), which can be crystalline, into a powder consisting of mostly single particles. The neodymium, iron, and boron powder 910 can be combined with binder 912 to produce feedstock 920. Binder 912 can be formed from a polymer such as polyphenylene sulfide (PPS), polyamide or nylon, polyvinyl butyral, rubber, etc. The powder 910 and binder 912 can be mixed and granulated in process 914 to produce feedstock 920 for molding. The feedstock 920 can be heated and then injection molded in a mold, such as mold 810 (shown in FIG. 8), in molding process 930 to form what becomes magnet 820 (both shown in FIG. 8). During molding process 930, magnet 820 can be in a magnetic field, such as magnetic field 834 (ibid.). The magnetic field 834 may be a constant or variable magnetic field. The magnetic field 834 may be a current generated in either or both of the coils 830 and 832 and may be present during part or all of the molding process. The magnetic field 834 may be generated by one or more short bursts of current in either or both of the coils 830 and 832. The magnetic field 834 may be generated by the coils 830 and 832, or by magnetic elements such as other coils, permanent magnets, magnets, pole pieces, electromagnets, or other structures capable of transmitting or generating a magnetic field, or a combination thereof.

[0089] After shaping, the shaped material can be debonded in a debonding process 940. The debonding process 940 can be a thermal debonding. The debonding process 940 can alternatively be a catalytic debonding process, where the shaped material is debonded in a gaseous acid environment, where the acid is nitric acid, oxalic acid, or other acid. The debonding process 940 can be carried out using a solvent such as acetone, heptane, or other ketones.

[0090] After the debinding process 940, the result, which may be referred to as a green portion 950, may be sintered in a sintering process 960 to produce a finished product 970. The sintering process may remove some or all of the voids created during the debinding process 940. In these and other embodiments of the invention, the magnet 820 may include 2, 3, 4, or other percent voids. The molded material may be removed from the mold 810 for the debinding process 940 and sintering process 960.

[0091] After the sintering process 960, the grains of the finished product 970 remain aligned to form the desired easy axis. The sintering process 960 may remove some or all of the magnetism of the finished product 970. The finished product 970 may be magnetized at this point to become a full magnet. Alternatively, the finished product 970 may be placed into an electronic device while still unmagnetized and easy to handle. Once assembled, the finished product 970 may be magnetized to become the full magnet 820. In these and other embodiments of the invention, the finished product 970 may be magnetized at other times after sintering to become the full magnet 820.

[0092] During molding, coil 830 and coil 832 may share the same current or may have separate currents, which may have the same or different directions, durations, and magnitudes. Either or both of these currents may be constant or variable, i.e., their magnitudes may change over time. Either or both of these currents may be on for a duration that is at least a significant portion of the time required for the molding process. Either or both of these currents may be on for one or more short durations of relatively large magnitude, or a combination of such currents of longer and shorter durations may be used during the molding process.

[0093] FIG. 10 illustrates a method of manufacturing a magnet according to an embodiment of the present invention. In step 1010, a feedstock may be provided that includes a mixture of neodymium, iron, and boron, and a binder. The neodymium, iron, and boron may be a powder formed by grinding crystalline NdFeB into a powder consisting of mostly single particles. This powder may be combined with a binder and then mixed and granulated to form the feedstock. The feedstock may be heated in step 1020. In step 1030, a magnetic field may be applied to the mold. The magnetic field may be generated by one or more coils, permanent magnets, magnets, magnetic elements such as pole pieces, electromagnets, or other structures capable of conveying or generating a magnetic field, or a combination thereof. In step 1040, the feedstock may be injected into the mold. In these and other embodiments of the present invention, the feedstock may be injected into the mold and then the magnetic field may be applied, or these two events may occur simultaneously or nearly simultaneously.

[0094] At step 1050, some or all of the binder material may be removed from the molded magnet. At step 1060, the molded magnet may be sintered. At step 1070, the sintered magnet may be trimmed. The sintered magnet may be magnetized at this point, or later, the sintered magnet may be placed in an electronic device and magnetized. Placing the sintered magnet in an electronic device prior to magnetization makes the sintered magnet easier to handle.

[0095] FIG. 11 illustrates a coil configuration that may be used during the manufacture of a magnet according to an embodiment of the invention. In this example, a molding system 1100 may include a magnet 1110 and a coil 1120. The magnet 1110 may be formed in a mold, such as mold 810 (shown in FIG. 8), while a current is passed through the coil 1120 to generate a magnetic field 1122. The coil 1120 may generate a magnetic field 1122 that may radially align the easy axis of the magnet 1110 during molding. For example, the magnetic field 1122 may force the easy axis direction in a radially non-parallel manner, as shown by the easy axis direction 448, as shown in FIG. 4B.

[0096] The current in the coil 1120 can have a long duration that extends during part or all of the forming process. The current in the coil 1120 can be one or more short bursts, or these different types of current waveforms can be combined. The current in the coil 1120 can vary in magnitude over time. The current in the coil 1120 can be present during part or all of the forming process and form a magnetic field 1122, as described above.

[0097] Figure 12 is a diagram illustrating a coil configuration that can be used in manufacturing a magnet according to an embodiment of the invention. In this example, molding system 1200 can include magnet 1210, coil 1220, and coil 1222. Magnet 1210 can be formed in a mold, such as mold 810 (shown in Figure 8), while current is passed through coil 1220 and coil 1222 to generate magnetic field 1224. Coil 1220 and coil 1222 can generate magnetic field 1224 while being molded that can align the easy axis of magnet 1210 in a diverging, non-parallel manner.

[0098] Coil 1220 and coil 1222 can carry the same or different currents. The currents can flow in the same or opposite directions. Either or both of the currents in coil 1220 and coil 1222 can have a long duration that extends during part or all of the molding process. Either or both of the currents in coil 1220 and coil 1222 can be one or more short bursts, or these different types of current waveforms can be combined. Either or both of the currents in coil 1220 and coil 1222 can vary in magnitude over time. Either or both of the currents in coil 1220 and coil 1222 can be present during part or all of the molding process as described above to form magnetic field 1224. Either or both of coil 1220 and coil 1222 can be connected in series or parallel to a current source (not shown). Either or both of coil 1220 and coil 1222 can each be connected to a corresponding separate current source.

[0099] FIG. 13 illustrates a coil configuration that can be used in the manufacture of a magnet according to an embodiment of the present invention. In this example, a molding system 1300 can include a magnet 1310 and a coil 1320. The magnet 1310 can be formed in a mold, such as mold 810 (shown in FIG. 8), while a current is passed through the coil 1320 to generate a magnetic field 1322. The coil 1320 can generate a magnetic field 1322 that can align the easy axis of the magnet 1310 as a Halbach array while it is being molded. For example, the magnetic field 1322 can force the easy axis directions arranged as a Halbach array as shown by the polarities 790 to 798 in FIG. 7B.

[0100] Each of the coils 1320 can carry the same or different currents. The currents can flow in various directions. One or more of the currents in the coils 1320 can have a long duration that extends during part or all of the forming process. One or more of the currents in the coils 1320 can be one or more short bursts, or these different types of current waveforms can be combined. One or more of the currents in the coils 1320 can vary in magnitude over time. One or more of the currents in the coils 1320 can be present during part or all of the forming process as described above to form the magnetic field 1224. The one or more coils 1320 can be connected in series or parallel to a current source (not shown). The one or more coils 1320 can each be connected to a corresponding separate current source.

[0101] These and other embodiments of the present invention can provide magnets of other shapes. For example, embodiments can provide a conventional bar magnet. Commercially available bar magnets may not be available in the exact size required, and therefore such bar magnets can be manufactured more efficiently since material still needs to be removed to form the bar magnet. Also, embodiments can provide stronger magnets than are commercially available. Other shapes such as plus sign or "X" shaped magnets. These magnets can have a first polarity on two adjacent ends, or two opposing ends can have a first polarity and the remaining end has a second polarity. Ring magnets, "S" shaped magnets, horseshoe magnets, or magnets of other shapes can also be formed using embodiments of the present invention.

[0102] Embodiments of the present invention can provide a unitary magnet with different easy axis directions at different locations. Also, embodiments can provide a unitary magnet with one polarity direction throughout the magnet. Commercially available magnets may not be available in the exact size required, and therefore such magnets can be made more efficiently since material still needs to be removed to form a magnet with one polarity direction. Also, embodiments can provide stronger magnets than are commercially available.

[0103] It is understood that use of personally identifiable information should comply with privacy policies and practices generally recognized as meeting or exceeding industry or governmental requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of permitted uses should be clearly indicated to users.

[0104] The above description of the embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form described, as many modifications and variations are possible in light of the above teachings. The embodiments have been chosen and described to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to best utilize the invention in various embodiments, and with various modifications as may be suitable for the particular use contemplated. It will therefore be understood that the present invention is intended to cover all modifications and equivalents within the scope of the following claims.

Claims

1. 1. An electronic device comprising: a magnet formed as a unitary structure, the magnet comprising a first portion and a second portion; the first portion has a first easy axis and the second portion has a second easy axis, the first easy axis and the second easy axis being non-parallel.

2. The electronic device of claim 1 , wherein the magnet is formed by metal injection molding.

3. The electronic device of claim 2 , wherein the magnet is a rare earth magnet.

4. The electronic device of claim 2 , wherein the magnet is formed from neodymium, iron, and boron.

5. The electronic device of claim 4 , wherein the magnet includes at least one curved surface.

6. The electronic device of claim 5 , wherein the magnet comprises at least two percent air gap.

7. 1. An electronic device comprising: a magnet formed as a unitary structure, the magnet comprising a first portion and a second portion; the first portion has an easy axis direction along a first axis; the second portion has an easy axis direction along a second axis; The first axis and the second axis intersect.

8. The electronic device of claim 7 , wherein the magnet is formed by metal injection molding.

9. The electronic device of claim 8 , wherein the magnet is formed from neodymium, iron, and boron.

10. 10. The electronic device of claim 9, wherein the magnet is shaped as an arc of a circle, the circle having a center, and the first axis and the second axis intersect at the center of the circle.

11. The electronic device of claim 10 , wherein the magnet comprises at least two percent air gap.

12. 1. An electronic device comprising:

1. An electronic device comprising: a magnet formed as a unitary structure using metal injection molding, the magnet being formed from neodymium, iron, and boron, the magnet including multiple easy axes, the multiple easy axes being non-parallel.

13. The electronic device of claim 12 , wherein adjacent faces of the magnets form one of an acute angle or an obtuse angle.

14. The electronic device of claim 12 , wherein the easy axis of the magnet enters a first surface, rotates at least 180°, and exits the first surface.

15. The electronic device of claim 14 , wherein the first surface is curved.

16. a first side of the magnet has an easy axis direction in a first direction, a second side of the magnet has an easy axis direction in a second direction, and a center of the magnet has an easy axis direction in a third direction; 13. The electronic device of claim 12, wherein the third direction is from the second side of the magnet to the first side of the magnet, and the first direction and the third direction converge at an angle or an acute or obtuse angle.

17. 13. The electronic device of claim 12, wherein the surface of the magnet comprises an array of easy axis oriented groups, each easy axis oriented group having a first polarity or a second polarity, and each row in the array comprises an easy axis oriented group having the first polarity and an easy axis oriented group having the second polarity.

18. 20. The electronic device of claim 17, wherein each column in the array includes an easy axis group having the first polarity and an easy axis group having the second polarity.

19. The electronic device of claim 12 , wherein the magnet mimics a Halbach array.

20. 20. The electronic device of claim 19, wherein a magnetic field strength on a first side of the magnet is greater than a magnetic field strength on a second side of the magnet.

21. 1. An electronic device comprising:

1. An electronic device comprising: a magnet formed as a unitary structure using metal injection molding, the magnet being formed from neodymium, iron, and boron and having a single easy axis direction.

22. 22. The electronic device of claim 21, wherein adjacent faces of the magnet form one of an acute angle or an obtuse angle.

Images