PATENT DOCUMENT

Publication Number: US-10008325-B2
Application Number: US-201514733844-A
Country: US
Kind Code: B2

Title: Thin magnet fabrication

Abstract:
Manufacturing techniques for producing thin magnetic elements are designed to accommodate the mechanical properties of sintered magnetic substrates. One of the manufacturing processes involves cutting a magnetizable substrate into a number of slices and adhesively coupling the slices to a sheet that can take the form of a layer of grinding tape. After concurrently grinding a first surface of each of the slices, the slices are flipped over so that the first surface of each slice is attached to another layer of grinding tape. A second surface of each of the slices is then ground until a desired thickness is achieved. Subsequent to the grinding, dicing operations can be applied to the slices to produce magnets having a desired length and width.

Claims:
What is claimed is: 
     
       1. A method of manufacturing an ultra-thin magnet for use in a small form factor electronic component, the method comprising:
 cutting a substrate formed of magnetizable material into slices; 
 thinning the slices to form thinned slices by:
 mounting the slices to a first support structure; 
 removing a first amount of material from exposed first surfaces of the slices, 
 flipping the slices over and mounting the slices to a second support structure, and 
 removing a second amount of material from exposed second surfaces of the slices; 
 
 singulating the thinned slices into individual magnetic elements; and 
 magnetizing the individual magnetic elements in accordance with a desired magnetic property. 
 
     
     
       2. The method as recited in  claim 1 , wherein, while singulating the thinned slices, the individual magnetic elements are adhesively coupled to the second support structure. 
     
     
       3. The method as recited in  claim 1 , wherein, subsequent to removing the second amount of material, an overall thickness of each of the thinned slices is within a range of +1/−5 microns of a nominal thickness of each other. 
     
     
       4. The method as recited in  claim 1 , further comprising:
 magnetically coupling a ferrous substrate with each of the individual magnetic elements by placing the ferrous substrate in direct contact with a surface of the second support structure that is opposite to a surface of the second support structure that is in contact with the individual magnetic elements. 
 
     
     
       5. The method as recited in  claim 1 , wherein the first and second support structures include a layer of UV-curable adhesive for affixing the thinned slices, and wherein UV irradiation of the UV-curable adhesive generally reduces a strength of an adhesive bond between the thinned slices and the first and second support structures. 
     
     
       6. The method as recited in  claim 1 , wherein removing the first and second amounts of material includes applying grinding operations to the exposed first and second surfaces of each of the slices until the slices have a generally similar thickness. 
     
     
       7. The method as recited in  claim 1 , wherein singulating the thinned slices includes applying a number of sawing operations in a first direction and a number of sawing operations in a second direction orthogonal to the first direction. 
     
     
       8. The method as recited in  claim 1 , wherein each of the individual magnetic elements has a thickness that is less than 100 microns. 
     
     
       9. The method as recited in  claim 1 , further comprising:
 plating the individual magnetic elements with an anti-corrosive layer. 
 
     
     
       10. A method for forming an ultra-thin magnet for use in an electronic component for a portable electronic device, comprising:
 cutting a magnetizable substrate into slices; 
 removing a first amount of material from a first side of each of the slices while the slices are secured to a first adhesive support structure; 
 flipping the slices over and securing the slices to a second adhesive support structure; 
 removing a second amount of material from a second side of each of the slices that is opposite to the first side while the slices are secured to the second adhesive support structure until a desired thickness of each of the slices is achieved; 
 of singulating the slices into magnetic elements; and 
 magnetizing the magnetic elements. 
 
     
     
       11. The method as recited in  claim 10 , wherein, subsequent to magnetizing the magnetic elements, the method further comprises:
 detaching the magnetic elements from the second adhesive support structures; and 
 installing the magnetic elements on a printed circuit board (PCB) so that an exposed surface of each of the magnetic elements is coupled with a surface of the PCB. 
 
     
     
       12. The method as recited in  claim 10 , wherein singulating the slices includes using a linear cutting tool to cut the slices into the magnetic elements. 
     
     
       13. The method as recited in  claim 10 , wherein, subsequent to magnetizing the magnetic elements, the method further comprises:
 coupling a magnetically attractable plate to the second adhesive support structure, thereby fixing the magnetic elements in place on the second adhesive support structure. 
 
     
     
       14. The method as recited in  claim 10 , wherein the first adhesive support structure is a first adhesive sheet, and the second adhesive support structure is a second adhesive sheet. 
     
     
       15. The method as recited in  claim 14 , further comprising:
 irradiating the second adhesive sheet to reduce adhesive coupling between the first side of each of the slices and the second adhesive sheet; and 
 subsequently, separating each of the slices from the second adhesive sheet. 
 
     
     
       16. The method as recited in  claim 10 , further comprising:
 plating the first and second sides of the magnetic elements with an anti-corrosive layer.

Description:
FIELD 
     The described embodiments relate generally to methods for accurately forming and magnetizing thin magnetic substrates. In particular, methods for producing thin magnetic substrates while minimizing sample variation are discussed. 
     BACKGROUND 
     Modern magnet fabrication processes suffer from substantial sample variation as magnetic substrates of increasingly reduced thicknesses are produced. Often magnets formed by conventional processes begin suffering from substantial sample variation as a thickness of the magnets falls below 1 mm. Magnets of this size can be advantageous in the construction of small form factor electronic components. In some embodiments, a field strength and size of the magnets can be critical to achieving a desired field size. In some embodiments, a magnet having too much dimensional sample variation can prevent the magnet from being successfully packaged within one of the small form factor electronic components. In some embodiments, sample variations of a tenth of a millimeter or less can adversely affect the function and/or fit of one of the magnets. 
     SUMMARY 
     This paper describes various embodiments that relate to manufacturing methods for producing magnets having particularly small dimensions. 
     A manufacturing method is disclosed. The manufacturing method includes at least the following steps: cutting a substrate formed of magnetizable material into slices having an initial thickness greater than a desired thickness; removing portions of the slices until the desired thickness of the slices is achieved; singulating each of the slices into a number of magnetic elements while the slices are coupled with a support structure; and magnetizing the magnetic elements in accordance with a desired magnetic polarity pattern prior to removing the magnetic elements from the support structure. 
     A method is disclosed. The method includes at least the following steps: cutting a magnetizable substrate into a number of slices; grinding a first side of each of the slices; coupling the first side of each of the slices to an adhesive sheet; concurrently grinding a second side of each of the slices until a desired thickness of each of the slices is achieved, the second side being opposite the first side; dicing each of the slices into a number of magnetic elements having a desired length and width; plating exposed surfaces of each of the magnetic elements with an anti-corrosive layer; magnetizing the magnetic elements; and coupling a magnetically attractable plate to a surface of the adhesive sheet opposite the magnetic elements to keep the magnetic elements fixed in place on the adhesive sheet. 
     A non-transitory computer readable storage medium is described. The non-transient computer readable medium is configured to store instructions that, when executed by a processor in a computer numerical control (CNC) device, cause the CNC device to carry out a manufacturing method, by carrying out steps that include: cutting a sintered magnetic substrate into a number of slices having substantially similar geometries; adhesively coupling a first surface of each of the slices to a first adhesive sheet; grinding a second surface of each of the slices, the second surface being positioned opposite the first surface, until a desired surface finish is achieved on the second surface; adhesively coupling the second surface of each slice to a second adhesive sheet; separating the first surface of each of the slices from the first adhesive sheet; grinding the first surface of each of the slices until a desired thickness of each of the slices is reached; and dicing each of the slices into a number of magnetic elements. 
     Other aspects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, where like reference numerals designate like structural elements, and in which: 
         FIG. 1A  shows a magnetic substrate; 
         FIG. 1B  shows how slices of the magnetic substrate depicted in  FIG. 1A  can be arranged upon a layer of grinding tape; 
         FIG. 1C  shows how the slices can be flipped over after applying a grinding operation to a first surface of each of the slices; 
         FIG. 1D  shows how a dicing operation can be applied in a first direction; 
         FIG. 1E  shows how a subsequent dicing operation can be applied in a second direction offset from the first direction depicted in  FIG. 1D ; 
         FIG. 2A  shows a cross-sectional view of magnets affixed to a layer of grinding tape after having undergone a number of dicing operations; 
         FIG. 2B  shows a cross-sectional view of the magnets depicted in  FIG. 2A  in which an anti-corrosive layer has been applied to the magnetic elements; 
         FIG. 2C  shows the magnetic elements depicted in  FIG. 2B  undergoing a magnetizing operation; 
         FIGS. 2D-2E  show how a shielding element or mask can be utilized to produce an array of magnetic elements fixed to an adhesive sheet in which some of the magnets have different polarities; 
         FIG. 2F  shows how a magnetically attractable plate can be placed beneath a number of magnetic elements to prevent motion of a number of magnetized magnetic elements; 
         FIG. 2G  shows how one of the magnets can be installed upon another electrical component; 
         FIGS. 3A-3B  show flow diagrams depicting a method for forming a number of thin magnetic elements with high dimensional accuracy; and 
         FIG. 4  depicts a computing device suitable for carrying out some of the manufacturing processes described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     Sintered magnetic substrates can provide several manufacturing difficulties due to the material properties inherent to sintered magnetic substrates. For example, sintered magnetic substrates made from rare earth metals tend to be quite brittle, resulting in a low mechanical strength. For this reason, conventional manufacturing operations can subject the sintered magnetic substrates to cracking or fracture under stresses induced during the conventional manufacturing operations. Consequently, shaping operations are generally carried out utilizing cutting tools having extremely sharp edges that minimize mechanical stresses experienced by the sintered magnetic substrates. Unfortunately, even when extremely sharp edged cutting tools are utilized, getting consistent dimensional accuracy when shaping a sintered magnetic substrate to have a dimension of less than 500 microns can be quite challenging. Achieving a dimensional thickness of less than 100 microns during a cutting operation is generally considered to be infeasible. Dimensional variations resulting from the aforementioned types of cutting operations, in which a consistent dimensional accuracy cannot be reliably achieved, can have highly detrimental effects on yields of magnets formed from the sintered magnetic substrates. For this reason, alternative ways of forming thin magnet that include one or more dimensions of less than a millimeter are highly desired. 
     One solution to this problem is to cut the sintered magnetic substrates to a shape or geometry slightly larger than desired in a final magnet and then to apply grinding operations that alter the dimensions of the sintered magnetic substrate to a desired size and shape. In particular, the grinding operations can be particularly effective at reliably achieving magnet thicknesses as small as about 80 microns. As mentioned above, dimensional accuracy can be particularly critical when a desired dimension is particularly small. For example, when shaping a sintered magnetic substrate to have a final dimension of less than a millimeter, dimensional sample variations amounting to greater than 10 microns can begin to have substantial effects on an overall volume of the sintered magnetic material. The greater accuracy inherent with finely tuned grinding operations can provide the accuracy necessary to achieve consistent dimensional accuracies. In some embodiments, total thickness variation of the magnets can be tightly controlled to be within +/−5 microns, whereas traditional approaches yield accuracies that can vary by as much as +/−30 microns. In addition to providing very tight thickness control, the disclosed manufacturing methods also provide excellent parallelism, which results in very consistent thicknesses for magnets of the same batch as well as substantially parallel opposing surfaces of each produced magnet. The substantially parallel surfaces can be very helpful in many kinds of configurations where one or more of the magnets is stacked with other magnets or components. 
     These and other embodiments are discussed below with reference to  FIGS. 1A-4 ; however, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIGS. 1A-1E  illustrate a number of steps for forming thin magnetic substrates. The magnetic material for the magnetic substrates can be initially formed as part of a sintering operation in which magnetic material is formed into a shape suitable for further processing. It should be understood that the described processes can be applied to any magnetizable substrate but sintered magnetizable substrates will be used. In a first step illustrated by  FIG. 1A , sintered magnetizable material  100  is cut into a number of slices  102  having a thickness greater than a desired thickness of a finished magnet.  FIG. 1B  shows how slices  102  can be arranged upon and laminated to grinding tape  104  for further processing. In some embodiments, lamination of slices  102  to grinding tape  104  can be accomplished by a layer of UV curable adhesive arranged upon grinding tape  104 . The UV curable adhesive can be utilized so that magnetic substrate surface damage and contamination caused by infiltration of grinding fluid and/or debris can be prevented. In some embodiments, UV irradiation of the UV-curable adhesive can substantially reduce a strength of the adhesive bond between slices  102  and grinding tape  104  so that an amount of stress transferred to slices  102  can be minimized. While the slices are arranged upon grinding tape  104 , a grinding operation can be applied to upward facing surfaces  106  of slices  102  until a desired finish is achieved upon each of surfaces  106 . This initial grinding operation provides an opportunity to make each of slices  102  substantially the same thickness. After completing the initial grinding operation, slices  102  can be flipped over and adhered to another sheet of grinding tape  108  so that after grinding tape  104  is removed from surfaces  110  of slices  102 , surfaces  110  of slices  102  can be exposed, as depicted in  FIG. 1C . After surfaces  110  are exposed, a grinding operation can be applied to surfaces  110  until a desired surface finish and thickness of slices  102  are achieved. In some embodiments, the desired thickness can be on the order of between 80-200 microns. Subsequent to thinning the slices to the desired thickness, dicing operations can be applied to slices  102  by a linear cutting tool such as for example a diamond saw. 
       FIG. 1D  shows how a first set of cutting operations can be performed along the x-axis and then  FIG. 1E  shows how a second set of cutting operations can be performed along the y-axis. While the figures show each of the slices being diced into a rather limited number of magnetic substrates, it should be understood that the slices can be diced into any number of discrete magnetic substrates. Furthermore, a shape of the diced magnetic substrates can also vary widely. For example, triangular or other polygonal shapes can be achieved with the aforementioned linear cutting tool. In some embodiments, subsequent finishing operations can be applied to the resulting magnets before removing the diced magnets from grinding tape  108 . In some embodiments, an automated arm along the lines of a pick and place can be used to remove the magnets from the grinding tape and transfer them to another supporting/fixturing device for holding the magnets in place during various magnetizing and finishing operations. 
       FIGS. 2A-2C  show how in some embodiments anti-corrosion coating and magnetizing operations can be applied to magnetic elements  202  prior to removing magnetic elements  202  from grinding tape  108 .  FIG. 2A  shows a cross-sectional view in accordance with section line A-A of  FIG. 1E . The cross-sectional view of magnetic elements  202  are shown being adhered to grinding tape  108 . Each of magnetic elements  202  are separated from adjacent magnetic elements  202  by an interval  204 . Interval  204  can be created by the material removed from slices  102  during the dicing operations. In some embodiments, interval  204  can correspond to a thickness of the linear tool used to cut dice.  FIG. 2B  shows how an anti-corrosion coating  206  can be added to cover exposed surfaces of magnetic elements  202 . Addition of anti-corrosion coating  206  can narrow an interval between magnetic elements  202  from interval  204  to interval  208 ; however, a thickness of anti-corrosion coating can be particularly thin along the lines of about 30 microns. In some embodiments, anti-corrosion coating  206  can be formed of a nickel alloy. In other embodiments, other magnetically attractable coatings with suitable corrosion resistance can be utilized. 
       FIG. 2C  shows magnetic elements  202  arranged within a magnetizing coil  210  for carrying out a magnetizing operation. Magnetizing coil  210  includes a number of coils  212  that carry electricity that is used to generate a magnetizing field within magnetizing coil  210 . In some embodiments, an adhesive bond between grinding tape  108  and magnetic elements  202  can prevent magnetic elements  202  from shifting out of position subsequent to the magnetizing operation depicted in  FIG. 2C . In some embodiments, an adhesive bond between grinding tape  108  and magnetic elements  202  can be sufficient to withstand stresses induced by magnetic field interaction between magnetic elements  202  for a period of time. In some embodiments, grinding tape  108  can be supported within magnetizing coil  210  by a non-magnetic frame (not depicted) that doesn&#39;t interfere with the magnetizing operations. While a basic magnetizing coil is depicted it should be understood that more complex magnetizing coils can be utilized during a magnetizing operation. More complex fields may require separation of magnetic elements  202  from grinding tape  108 . 
       FIG. 2D  shows an alternative magnetization configuration. In particular, shielding element  215  can be added above and/or below magnetic elements  202  to prevent magnetization of the magnets overlaid by shielding elements  215 . Shielding element  215  can be formed of materials that redirect magnetic fields around shielding elements  215 , as depicted. Preventing magnetization of certain magnets, allows a subsequent magnetizing operation to be carried out in which the magnetized magnets are covered and the unmagnetized magnets are exposed to a magnetizing field having different characteristics. In some embodiments, the emitted fields can be in the same direction but varied so that some magnets attached to the grinding tape are stronger than others. In some embodiments, the emitted fields can be oriented in different directions.  FIG. 2E  shows a top view of a two dimensional array of magnets, suitable for being magnetized within magnetizing coil  210 , in which some of the adjacent magnets have a first polarity (P 1 ) and others have a second polarity (P 2 ). In some embodiments, shielding element  215  can take the form of a mask that shields certain magnets of the two dimensional magnet array from being exposed to a magnetizing field emitted by magnetizing coil  210 . A shape of the mask when applying the magnetizing field for the P 2  polarities can correspond to the dashed lines depicted in  FIG. 2E . In some embodiments, the mask can be formed of numerous shielding elements  215 . In some embodiment, by applying different magnetic fields to different magnets in the two dimensional array, at least some of the magnets from the array can be transferred together to a device designed to operate with the pattern of emitted magnetic fields established by the sequential magnetizing operations. 
       FIG. 2F  shows a step in which a magnetically attractable plate is added beneath grinding tape  108  to prevent shearing of the adhesive bonds between grinding tape  108  and magnetic elements  202 . The shearing forces can be generated when magnetic field emitted by adjacent magnetic elements  202  interact with and attract each other. The magnetic attraction between magnetically attractable plate  214  and magnetic elements  202  can cooperate with the adhesive bond coupling grinding tape  108  to magnetic elements  202  so that magnetic elements  202  are kept firmly in place for any follow on manufacturing processes. For example, precise placement of magnetic elements  202  on grinding tape  108  can be helpful when computer controlled machinery is utilized to manipulate and assembly magnetic elements  202  into various electronic devices. In some embodiments, magnetically attractable plate  214  can be adhesively coupled to a surface of grinding tape  108 . In some embodiments, various clamping mechanisms or other securing means can be used to keep magnetically attractable plate  214  in contact with grinding tape  108 . Magnetic forces between magnetic elements  202  and magnetically attractable plate  214  can also assist in maintaining a coupling with magnetically attractable plate  214  during subsequent manufacturing and/or assembly operations. 
     In  FIG. 2G , one of magnetic elements  202  is depicted after having been separated from grinding tape  108 . Arrow  216  shows a possible path taken while moving magnetic element  202  from grinding tape  108  to substrate  218 . In some embodiments, a pick and place can be used to remove magnetic element  202  from grinding tape  108  and install magnetic element  202  on substrate  218 . In some embodiments, substrate  218  can take the form of a printed circuit board (PCB). While removing magnetic element  202  from grinding tape  108 , the pick and place can be configured to exert an amount of force on magnetic element  202  sufficient to sever an adhesive bond between magnetic element  202  and grinding tape  108  while also overcoming a force generated by magnetic interaction between magnetic element  202  and magnetically attractable plate  214 . It should be noted that magnetically attractable plate  214  can take the form of a sheet of steel or any other ferrous material. 
     In some embodiments, the attachment of magnetic elements  202  to substrate  218  should be conducted quickly to avoid undue exposure of an exposed surface of magnetic element  202  to corrosive molecules in the air. In some embodiments, the pick and place step can be performed under near vacuum conditions to prevent exposure of the exposed surface of magnetic element  202  to the aforementioned corrosive molecules. Once mounted to substrate  218 , anti-corrosive coating  206  in cooperation with substrate  218  can prevent magnetic element  202  from being exposed to any potentially corrosive gases. In some embodiments, substrate  218  can take the form of a printed circuit board (PCB). Such a configuration can allow the PCB to act as both a carrier for magnetic element  202  and to support other electrical components such as processors and other discrete electrical components. In some embodiments, a shunt or shielding device can be arranged around magnetic element  202  to help shield other electrical components mounted to the PCB. The shunt can also be utilized to concentrate a magnetic field emitted by magnetic element  202  towards a location in which a magnetic field emitted by the magnet is designed to act. In some embodiments, the magnet positioned upon the PCB can be integrated into a voice coil motor (VCM). In certain cases the reduced thickness achieved by the aforementioned machining operations can produce a VCM with particularly small dimensions that can reduce an overall size of a camera module utilizing the VCM. For example, the VCM can be utilized to drive an autofocus component of the camera module without significantly adding to an overall size of the camera module. 
       FIGS. 3A-3B  show a block diagram representing a method for forming thin magnets.  FIG. 3A  includes a first step  302 , where a sintered magnetic substrate is formed. In some embodiments, the magnetic substrate can be a composite magnetic substrate along the lines of a Neodymium or Samarium-Cobalt magnets. The sintering process involves melting down the various raw materials necessary to form the magnetic metal alloys. The melting process can be performed in an induction melting furnace. After liquefying the various metals, the molten metals can be poured into thin metal strips that can then be crushed and/or pulverized to form a fine powder. The fine powder is then compressed or compacted together. An aligning magnetic field is generally applied during the compression to align the crystalline structure of the magnetic structure in a desired direction. The compression can be applied to an amount of material that forms a magnetic substrate having a slightly larger size than that desired. Subsequent to the compression and particle alignment step the compressed powder is loaded into a container and heated to a sintering temperature within for example a vacuum sintering furnace. The heating portion of the sintering process tends to shrink the compressed powder down by at least 10-15%. Magnetic substrates formed in this manner tend to exhibit no external magnetic field subsequent to being cooled after reaching the sintering temperature. At step  304 , the sintered magnetic substrate is cut into a number of slices having about the same size and thickness. In some embodiments, a manner in which the slices are cut can influence a magnetic direction of resulting magnets produced by this process. Unfortunately, the above described sintering process tends to produce a magnetic substrate with substantial variations in shape and surface properties/roughness. 
     At step  306 , slices of the magnetic substrate are affixed to a layer of grinding tape. In some embodiments, the magnetic substrate can be adhesively fixed to the layer of grinding tape with UV curable adhesive. At step  308 , an exposed layer of each slice undergoes a grinding operation in which a desired finish is produced and in some embodiments, a uniform thickness of each of the slices is achieved. In some embodiments, the desired finish can increase a surface energy of the surface to enhance adhesion between the surface of the slice and another object. At step  310 , the ground surfaces of the magnetic substrates are adhesively affixed to another layer of grinding tape. After affixing the magnetic substrates to the other layer of grinding tape, the first layer of grinding tape can be removed to reveal an opposite side of each of the magnetic substrates. In some embodiments, when the slices are affixed to the other layer of grinding tape with the UV curable adhesive, the UV curable adhesive can be irradiated to reduce adhesive coupling between the slices and the other layer of grinding tape. At step  312 , each of the magnetic substrates can undergo another grinding operation until the slices are thinned to a desired thickness. 
     The steps in the method continue in  FIG. 3B  at step  314  in which each of the ground magnetic slices undergo a series of dicing operations to produce a number of magnets from each magnetic substrate. The dicing operations can be performed as part of a computer controlled machining operation, giving the dicing blades or saws greater degrees of accuracy and precision. In some embodiments, the dimensional accuracy of the cuts made by the dicing blade or saw can be accurate to within +/−10 microns. At step  316 , an anti-corrosive layer is plated onto each of the magnets. In some embodiments, the anti-corrosive layer can coat or cover only five sides of each of the magnets. This configuration can result when the magnets remain affixed to a layer of grinding tape. By leaving a side of the magnet uncoated an overall thickness of the magnet can be reduced. This can be especially beneficial when the uncoated surface is designed to be permanently adhered to another surface, when that surface can provide sufficient anti-corrosive properties to the magnet. In embodiments where the anti-corrosive layer is desired on all surfaces the magnets can be separated from the grinding tape prior to a plating or coating operation. The plating operation can be performed by electrolysis or other deposition processes. The anti-corrosive layer can be formed from any one of a number of materials. Some examples of appropriate materials for use as anti-corrosive coatings can include Nickel, copper, zinc, gold, silver, tin, titanium, and chrome to name a few. Subsequent to adding the anti-corrosive plating the magnets can undergo magnetizing operations at step  318 . In some embodiments, magnetizing coils can be configured to apply a magnetic field that aligns with a grain or crystal structure of the magnetic substrates. In this way, an amount of magnetic energy applied to the magnet can be optimized. Finally, at step  320 , each of the magnets can be attached to a product for end use. In some embodiments, the magnets can form part of an electromagnetic system such as a voice coil motor. In other embodiments, the magnets can be employed for use as part of an attachment system. 
       FIG. 4  is a block diagram of an electronic device suitable for controlling some of the processes in the described embodiment. Electronic device  400  can illustrate circuitry of a representative computing device. Electronic device  400  can include a processor  402  that pertains to a microprocessor or controller for controlling the overall operation of electronic device  400 . Electronic device  400  can include instruction data pertaining to operating instructions in a file system  404  and a cache  406 . File system  404  can be a storage disk or a plurality of disks. In some embodiments, file system  404  can be flash memory, semiconductor (solid state) memory or the like. The file system  404  can typically provide high capacity storage capability for the electronic device  400 . However, since the access time to the file system  404  can be relatively slow, the electronic device  400  can also include cache  406 . The cache  406  can include, for example, Random-Access Memory (RAM) provided by semiconductor memory. The relative access time to the cache  406  can substantially shorter than for the file system  404 . However, cache  406  may not have the large storage capacity of file system  404 . Further, file system  404 , when active, can consume more power than cache  406 . Power consumption often can be a concern when the electronic device  400  is a portable device that is powered by battery  424 . The electronic device  400  can also include a RAM  420  and a Read-Only Memory (ROM)  422 . The ROM  422  can store programs, utilities or processes to be executed in a non-volatile manner. The RAM  420  can provide volatile data storage, such as for cache  406 . 
     Electronic device  400  can also include user input device  408  that allows a user of the electronic device  400  to interact with the electronic device  400 . For example, user input device  408  can take a variety of forms, such as a button, keypad, dial, touch screen, audio input interface, visual/image capture input interface, input in the form of sensor data, etc. Still further, electronic device  400  can include a display  410  (screen display) that can be controlled by processor  402  to display information to the user. Data bus  416  can facilitate data transfer between at least file system  404 , cache  406 , processor  402 , and controller  413 . Controller  413  can be used to interface with and control different manufacturing equipment through equipment control bus  414 . For example, control bus  414  can be used to control a computer numerical control (CNC) mill, a press, or other manufacturing devices. For example, processor  402 , upon a certain manufacturing event occurring, can supply instructions to control another manufacturing device through controller  413  and control bus  414 . Such instructions can be stored in file system  404 , RAM  420 , ROM  422  or cache  406 . 
     Electronic device  400  can also include a network/bus interface  411  that couples to data link  412 . Data link  412  can allow electronic device  400  to couple to a host computer or to accessory devices. The data link  412  can be provided over a wired connection or a wireless connection. In the case of a wireless connection, network/bus interface  411  can include a wireless transceiver. Sensor  426  can take the form of circuitry for detecting any number of stimuli. For example, sensor  426  can include any number of sensors for monitoring such as, for example, a Hall Effect sensor responsive to external magnetic field, an audio sensor, a light sensor such as a photometer and so on. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20150608
Publication Date: 20180626
Grant Date: 20180626
Priority Date: 20150608
Inventors: KRIMAN, MOSHE
MAGEN, ADAR
Assignee: APPLE INC
CPC Classifications: [{"code": "H02K1/2706", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02K1/2786", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F27/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H02K15/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F41/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49075", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49078", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T156/1917", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F10/007", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F41/0253", "inventive": true, "first": true, "tree": "[]"}, {"code": "H02K1/2793", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F13/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T156/1917", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T156/1917", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49078", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49078", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49075", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02K15/03", "inventive": false, "first": false, "tree": "[]"}, {"code": "H02K1/2706", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F41/026", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F41/0253", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01F41/0253", "inventive": true, "first": true, "tree": "[]"}, {"code": "H01F27/38", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F13/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F13/003", "inventive": true, "first": false, "tree": "[]"}, {"code": "H01F10/007", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49075", "inventive": false, "first": false, "tree": "[]"}, {"code": "H01F41/026", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 57451984