Thin magnet fabrication

Patent metadata

Field	Value
Publication number	US-10008325-B2
Application number	US-201514733844-A
Country	US
Kind code	B2
Filing date	Jun 8, 2015
Priority date	Jun 8, 2015
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

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.

First claim

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.

Assignees

• Apple Inc

Inventors

• Kriman Moshe
• Magen Adar

Classifications

• H02K1/2706

  Inner rotors · CPC title

• H02K1/2786

  Outer rotors · CPC title

• H01F27/38

  Auxiliary core members; Auxiliary coils or windings · CPC title

• H02K15/03

  having permanent magnets · CPC title

• H01F41/026

  protecting methods against environmental influences, e.g. oxygen, by surface treatment (magnetic particles with skin H01F1/061, H01F1/09, H01F1/24, H01F1/33 and G11B5/706) · CPC title