Magnetic sheet, electronic device using same, and method for manufacturing magnetic sheet

Patent metadata

Field	Value
Publication number	US-10020104-B2
Application number	US-201414780188-A
Country	US
Kind code	B2
Filing date	Mar 27, 2014
Priority date	Mar 28, 2013
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

Provided is a magnetic sheet including a resin film and a thin sheet-shaped magnetic body adhered to the resin film by an adhesive layer sandwiched between the thin sheet-shaped magnetic body and the resin film. The thin sheet-shaped magnetic body is made from an Fe-based metal magnetic material, has a thickness of 15 μm to 35 μm, and has an AC relative magnetic permeability (μ r ) in the range of 220 to 770 at a frequency of 500 kHz.

First claim

The invention claimed is:

1. A magnetic sheet comprising:
a resin film; and
a thin sheet-shaped magnetic body adhered to the resin film by an adhesive layer sandwiched between the thin sheet-shaped magnetic body and the resin film, the thin sheet-shaped magnetic body made from an Fe-based metal magnetic material,
wherein the Fe-based metal magnetic material is represented by the following formula: Fe 100-a-b-c B a Si b C c , and a, b, and c respectively satisfy 7≤a≤20, 8≤b≤19, 0≤c≤4, and 75≤100-a-b-c≤85 in atom %,
wherein the Fe-based metal magnetic material is made from an amorphous alloy and Fe 3 Si is precipitated in at least a part of the amorphous alloy, and
wherein the thin sheet-shaped magnetic body has a thickness of 15 μm to 35 μm; and
the thin sheet-shaped magnetic body has an AC relative magnetic permeability μr of 220 or more and 770 or less at a frequency of 500 kHz.

2. The magnetic sheet according to claim 1 , wherein a plurality of thin sheet-shaped magnetic bodies are attached to the resin film in a state where the thin sheet-shaped magnetic bodies are disposed next to each other on the resin film.

3. The magnetic sheet according to claim 1 , wherein the thin sheet-shaped magnetic body is divided into a plurality of pieces while the thin sheet-shaped magnetic body is maintained in a state of being adhered to the resin film.

4. The magnetic sheet according to claim 1 , wherein the thin sheet-shaped magnetic body is in a non-crack state.

5. An electronic device comprising:
the magnetic sheet according to claim 1 ; and
an electronic compass disposed closely to the magnetic sheet, the electronic compass including a geomagnetic sensor.

6. An electronic device comprising:
the magnetic sheet according to claim 2 ; and
an electronic compass disposed closely to the magnetic sheet, the electronic compass including a geomagnetic sensor.

7. An electronic device comprising:
the magnetic sheet according to claim 3 ; and
an electronic compass disposed closely to the magnetic sheet, the electronic compass including a geomagnetic sensor.

8. An electronic device comprising:
the magnetic sheet according to claim 4 ; and
an electronic compass disposed closely to the magnetic sheet, the electronic compass including a geomagnetic sensor.

Assignees

• Hitachi Metals Ltd

Inventors

• Watanabe Mitsuhiro
• Miki Hirohiko
• Nakamura Masaki

Classifications

• H01F10/14

  containing iron or nickel ({H01F10/126} , H01F10/13, H01F10/16 take precedence) · CPC title

• H01F10/142

  containing Si · CPC title

• H01F27/365

  Electricity · mapped topic

• G01C17/28

  Electromagnetic compasses (with north seeking magnetic elements and having electric pick-offs G01C17/26) · CPC title

• H01F1/16

  in the form of sheets (H01F1/147 takes precedence) · CPC title