Multilayer structures for magnetic shielding

• US 8,399,964 B2
• Filed: 08/23/2010
• Issued: 03/19/2013
• Est. Priority Date: 06/02/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Katti, Romney R.
• Primary Examiner(s): YEUNG LOPEZ, FEIFEI
• Application Number:
  US12/861,442
• Publication Number:
  US 20110316129A1
• Time in Patent Office: 939 Days
• Field of Search: None
• US Class Current: 257/659
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/49109 outside the semiconductor or solid-state body
• CPC Class Codes: H01L 23/552 Protection against radiation, e.g. light or electromagnetic waves
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/15156 Side view
• CPC Class Codes: H01L 2924/16195 Flat cap [not enclosing an internal cavity]
• CPC Class Codes: H05K 9/0075 Magnetic shielding materials
• CPC Class Codes: H05K 9/0088 comprising a plurality of shielding layers; combining different shielding material structure

Abstract

A magnetic shield is presented. The shield may be used to protect a microelectronic device from stray magnetic fields. The shield includes at least two layers. A first layer includes a magnetic material that may be used to block DC magnetic fields. A second layer includes a conductive material that may be used to block AC magnetic fields. Depending on the type of material that the first and second layers include, a third layer may be inserted in between the first and second layers. The third layer may include a non-conductive material that may be used to ensure that separate eddy current regions form in the first and second layers.

Claims

1. A system comprising:

a microelectronic device;

a first magnetic shield mounted to a first side of at least one of the microelectronic device or a package within which the microelectronic device is positioned, wherein the first magnetic shield is substantially planar, and wherein the first magnetic shield comprises;

a first layer comprising a first magnetic conductive material,

a second layer comprising a second magnetic conductive material, and

a third layer comprising a first non-conductive material, wherein the third layer is interposed between the first layer and the second layer and wherein each of the first and second layers is directly adjacent to the third layer,

wherein the first layer is defined by a first thickness that is greater than about 10 mils and the second layer is defined by a second thickness that is greater than about 10 mils; and

a second magnetic shield separated from the first magnetic shield by the microelectronic device, wherein the second magnetic shield comprises;

a fourth layer comprising at least one of a third magnetic conductive material or a first non-magnetic conductive material,

a fifth layer comprising at least one of a fourth magnetic conductive material or a second non-magnetic conductive material, and

a sixth layer comprising a second non-conductive material, wherein the sixth layer is interposed between the fourth layer and the fifth layer.

2. The system of claim 1, wherein each of the first magnetic conductive material and the second magnetic conductive material and the second magnetic conductive material comprises a high permeability material selected from the group consisting of NiFe and NiMoFe.

3. The system of claim 1, wherein the non-conductive material comprises at least one of an epoxy, a ferrite material, or a dielectric material.

9. The system of claim 1, wherein the first magnetic shield is mounted to the first side via at least one of a conductive epoxy or a non-conductive epoxy.

10. The system of claim 1, wherein each of the first layer, the second layer, and the third layer is a laminate film.

4. A shielded microelectronic device comprising:

a microelectronic device;

a first magnetic shield positioned above the microelectronic device, wherein the first magnetic shield comprises a first layer for attenuating a direct current magnetic field, a second layer for attenuating the direct current magnetic field, and a third layer interposed between the first layer and the second layer; and

a second magnetic shield positioned below the microelectronic device, wherein the second magnetic shield comprises a fourth layer for attenuating the direct current magnetic field, a fifth layer for attenuating the direct current magnetic field, and a sixth layer interposed between the fourth layer and the fifth layer,

wherein each of the first, second, fourth, and fifth layers comprises a conductive material and wherein each of the third and sixth layers comprises a non-conductive material.

5. The shielded microelectronic device as in claim 4, wherein the first layer is defined by a thickness that is greater than about 10 mils and the fourth layer is defined by a thickness that is greater than about 10 mils.

6. The shielded microelectronic device as in claim 4, wherein each of the first and fourth layers comprises a magnetic conductive material.

11. The system of claim 4, wherein the first magnetic shield is physically separated from the second magnetic shield by the microelectronic device.

12. The system of claim 4, wherein the first and second magnetic shields are mounted to at least one of the microelectronic device or a package within which the microelectronic device is positioned.

13. The system of claim 6, wherein the magnetic conductive material comprises a high permeability material selected from the group consisting of NiFe and NiMoFe.

14. The system of claim 4, wherein each of the first, second, third, fourth, fifth, and sixth layers is a laminate film.

7. A system comprising:

a microelectronic device;

a first magnetic shield positioned above the microelectronic device, wherein the first magnetic shield comprises a first layer comprising a first conductive material and configured to attenuate direct current magnetic fields, a second layer comprising a second conductive material and configured to attenuate direct current magnetic fields, and a third layer comprising a non-conductive material and interposed between the first and second layers; and

a second magnetic shield positioned below the microelectronic device, wherein the second magnetic shield comprises a fourth layer configured to attenuate direct current magnetic fields and a fifth layer configured to attenuate direct current magnetic fields.

8. The system of claim 7, wherein each of the first magnetic conductive material and the second magnetic conductive material comprises a high permeability material selected from the group consisting of NiFe and NiMoFe.

15. The system of claim 7, wherein the first magnetic shield is physically separated from the second magnetic shield by the microelectronic device.

16. The system of claim 7, wherein the first and second magnetic shields are mounted to at least one of the microelectronic device or a package within which the microelectronic device is positioned.

17. The system of claim 7, wherein each of the first, second, third, fourth, and fifth layers is a laminate film.