EMI absorbing shielding for a printed circuit board

1. An EMI shield comprising:

a shield body comprising a conductive layer coupled to a polymer substrate;

a polymer layer coupled to the conductive layer;

an EMI absorbing material coupled to the polymer layer

wherein the EMI absorbing material comprises an open-celled skeletal structure and the open-celled skeletal structure comprises a reticulated foam; and

wherein the reticulated foam comprises a metal layer on all interior surfaces and on all exterior surfaces except a lower surface that is configured to be in contact with at least one of a printed circuit board, an electronic component, or traces on the printed circuit board.

2. The EMI shield of claim 1 wherein the EMI absorbing material is electrically coupled to the conductive layer through an opening in the polymer layer.

3. The EMI shield of claim 1 wherein the open-celled skeletal structure is conductive.

4. The EMI shield of claim 1 wherein the shield body comprises a top surface and a plurality of sidewalls that extend at an angle from the sidewalls so as to define a chamber that receives an electronic component.

5. The EMI shield of claim 4 wherein the EMI absorbing material only partially fills the chamber defined by the shield body.

6. The EMI shield of claim 4 wherein the EMI absorbing material substantially fully fills the chamber defined by the shield body.

7. The EMI shield of claim 1 wherein the reticulated foam comprises a metal layer throughout the open-celled skeletal structure so as to maintain electrical continuity throughout the open-celled skeletal structure.

8. The EMI shield of claim 1 wherein the reticulated foam comprises between about 10 pores per inch and about 80 pores per inch.

9. The EMI shield of claim 1 wherein the metal layer comprises an average thickness of less than about 1.0 micron over the open-celled skeletal structure.

10. The EMI shield of claim 9 wherein the metal layer comprises a volume resistivity of between about 50 ohms and about 500 ohms.

11. The EMI shield of claim 10 wherein the metal layer on the open-celled skeletal structure comprises a higher resistivity than the conductive layer.

12. The EMI shield of claim 1 wherein the EMI absorbing material comprises a higher permittivity and a higher permeability than the conductive layer.

13. The EMI shield of claim 1 wherein the EMI absorbing material comprises a Mu-metal.

14. The EMI shield of claim 1 wherein the EMI absorbing material comprises a carbon felt.

15. The EMI shield of claim 1 wherein the polymer layer comprises polyurethane, polyethethylene, polyethethylene terephthalate, polypropylene, polyvinyl chloride, polycarbonate, or polybutylene terephthalate.

16. The EMI shield of claim 1 wherein the polymer layer is thinner than the polymer substrate.