Systems and methods for providing electromagnetic interference (EMI) shielding between inductors of a radio frequency (RF) module

Patent metadata

Field	Value
Publication number	US-10271421-B2
Application number	US-201715499657-A
Country	US
Kind code	B2
Filing date	Apr 27, 2017
Priority date	Sep 30, 2016
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

Electrically-conductive wires are used to construct an EMI shield between inductors of an RF module that prevents, or at least reduces, EMI crosstalk between the inductors while maintaining high Q factors for the inductors. The EMI shield comprises at least a first set of electrically-conductive wires that at least partially surrounds and extends over at least a first inductor of a pair of inductors. Adjacent wires of the first set are spaced apart from one another by a predetermined distance selected to ensure that the EMI shield attenuates a frequency or frequency range of interest. First and second ends of each of the wires are connected to an electrical ground structure. A length of each wire in between the first and second ends of the respective wire extends above the first inductor and is spaced apart from the first inductor so as not to be in contact with the first inductor.

First claim

What is claimed is:

1. A radio frequency (RF) module comprising:
a multi-layer substrate having a plurality of layers and a top surface, the plurality of layers including at least N layers of metal, where N is a positive integer that is greater than or equal to 1;
at least first and second inductors disposed in the multi-layer substrate, each of the first and second inductors having at least N coils, the first and second inductors having first and second axes, respectively, that are substantially perpendicular to the top surface of the multi-layer substrate, each coil being disposed in a respective layer of metal of the N layers of metal; and
at least a first electromagnetic interference (EMI) shield at least partially surrounding and extending over the first inductor, the first EMI shield being electrically coupled to an electrical ground structure of the multi-layer substrate, the first EMI shielding reducing EMI crosstalk between the first and second inductors, the first EMI shield comprising at least a first set of electrically-conductive wires, each electrically-conductive wire comprising: a first wire portion; a second wire portion; a third wire portion; and first and second bends where the first and second wire portions, respectively, transition into the third wire portion, wherein the third wire portion is substantially parallel to a top surface of the multilayer substrate.

2. The RF module of claim 1 , wherein the first and second wire portions have first ends that are electrically coupled to the electrical ground structure of the multi-layer substrate, the third wire portion extending between the first and second wire portions.

3. The RF module of claim 2 , wherein the first wire portions are substantially parallel to one another and substantially perpendicular to the top surface of the multi-layer substrate, wherein the second wire portions are substantially parallel to one another and to the first wire portions and substantially perpendicular to the top surface of the multi-layer substrate, and wherein the third wire portions are substantially parallel to one another and substantially parallel to the top surface of the multi-layer substrate.

4. The RF module of claim 3 , wherein when electrical current flows in the first and second inductors, the first and second inductors generate first and second magnetic fluxes, respectively, that are substantially parallel to the first and second axes, respectively, and substantially perpendicular to the third wire portions.

5. The RF module of claim 4 , wherein the third wire portions are at an angle, β, relative to a line drawn between the first and second axes perpendicular to the first and second axes, and wherein the angle β ranges between 0° and 359°.

6. The RF module of claim 4 , wherein the third wire portions are at a non-zero-degree angle β relative to a line drawn between the first and second axes perpendicular to the first and second axes.

7. The RF module of claim 4 , wherein adjacent electrically-conductive wires are spaced apart from one another by a lateral distance, D L , and wherein D L is constant for all of the electrically-conductive wires.

8. The RF module of claim 4 , wherein adjacent electrically-conductive wires are spaced apart from one another by a later distance, D L , and wherein D L is greater than or equal to 150 micrometers.

9. The RF module of claim 4 , wherein the third wire portions of the electrically-conductive wires are spaced apart from the top surface of the multi-layer substrate by a vertical distance, D V , and wherein D V is constant for all of the third wire portions.

10. The RF module of claim 4 , wherein the electrically-conductive wires are bond wires.

11. The RF module of claim 4 , wherein the electrically-conductive wires have a thickness, T, that ranges from about 10 micrometers (microns) to about 500 microns.

12. The RF module of claim 11 , wherein the thickness, T, ranges from about 12 microns to about 60 microns.

13. A radio frequency (RF) module comprising:
a multi-layer substrate having a plurality of layers and a top surface, the plurality of layers including at least N layers of metal, where N is a positive integer that is greater than or equal to 1;
at least first and second inductors disposed in the multi-layer substrate, the first and second inductors having first and second axes, respectively, that are substantially perpendicular to the top surface of the multi-layer substrate, each of the first and second inductors having at least N coils, wherein each coil is disposed in a respective layer of metal of the N layers of metal; and
at least a first electromagnetic interference (EMI) shield at least partially surrounding and extending over the first inductor, the first EMI shield being electrically coupled to an electrical ground structure of the multi-layer substrate, the first EMI shield comprising at least a first set of electrically-conductive wires having first and second ends that are electrically coupled to the electrical ground structure, each electrically-conductive wire having a wire portion that extends between the first and second ends of the respective electrically-conductive wire substantially parallel to the top surface of the multi-layer substrate, and bends where the first and second ends transition to the wire portion, wherein the first EMI shielding reduces EMI crosstalk between the first and second inductors.

14. The RF module of claim 13 , wherein the wire portion has an end that is electrically coupled to the electrical ground structure of the multi-layer substrate.

15. The RF module of claim 13 , wherein when electrical current flows in the first and second inductors, the first and second inductors generate first and second magnetic fluxes, respectively, that are substantially parallel to the first and second axes, respectively, and substantially perpendicular to the wire portion.

16. The RF module of claim 15 , wherein the wire portion is at an angle, β, relative to a line drawn between the first and second axes perpendicular to the first and second axes, and wherein the angle β ranges between 0° and 359°.

17. The RF module of claim 15 , wherein the wire portion is at a non-zero-degree angle β relative to a line drawn between the first and second axes perpendicular to the first and second axes.

Assignees

• Avago Technologies General Ip
• Avago Tech Int Sales Pte Lid

Inventors

• Gebauer Bernhard
• Wiedenmann Oliver
• Haney Sarah
• Elbrecht Lueder
• Choi Deog-Soon
• Lee Aaron

Classifications

• H05K1/165 Primary

  incorporating printed inductors · CPC title

• H01F41/041

  Printed circuit coils (apparatus or processes for manufacturing printed circuits in general H05K3/00) · CPC title

• H05K3/30

  Assembling printed circuits with electric components, e.g. with resistors · CPC title

• H01F27/2804

  Printed windings · CPC title

• H01F2027/2809

  on stacked layers · CPC title