Conductive stiffener for a flexible substrate

1. A structure for providing rigidity to an area of less than all of the area of a flexible substrate, the structure comprising:

a first adhesive over a certain area of the flexible substrate, the first adhesive having an opening over an electrical conducting portion of the flexible substrate and adhering to a portion of the structure that is adjacent to a lower surface of the first adhesive;

an electrically insulating layer between the first adhesive and the flexible substrate, wherein the electrically insulating layer includes an opening approximately located under the opening of the first adhesive, the opening of the electrically insulating layer approximating the size of the opening of the first adhesive;

an electrically conducting layer between the first adhesive and the electrically insulating layer, wherein the electrically conducting layer includes an opening approximately located under the opening of the first adhesive, the opening of the electrically conducting layer approximating the size of the opening of the first adhesive;

a second adhesive within a cavity defined by the opening of the first adhesive, wherein the second adhesive is electrically conducting, and wherein the second adhesive is disposed over and adjacent to the electrically conducting portion of the flexible substrate; and

a stiffener adhered to the structure by both the first and the second adhesive, wherein the stiffener is in contact with each of the first and second adhesives.

2. The structure according to claim 1 , wherein the first adhesive is a thermal set adhesive tape.

3. The structure according to claim 1 , wherein the second adhesive is a metal filled epoxy.

4. The structure according to claim 3 , wherein the metal of the second adhesive is silver.

5. The structure according to claim 1 , wherein the stiffener includes metal.

6. The structure according to claim 1 , wherein the stiffener includes stainless steel.

7. The structure according to claim 6 , wherein the stainless steel stiffener further includes nickel electroplating.

8. The structure according to claim 7 , wherein the nickel plated stainless steel stiffener further includes gold electroplating.

9. The structure according to claim 7 , wherein the electroplated nickel thickness is approximately fifty to one hundred microinches.

10. The structure according to claim 7 , wherein the nickel electroplating is sulfamate nickel.

11. The structure according to claim 8 , wherein the electroplated gold thickness is at least approximately three microinches.

12. A structure, comprising:

a flexible circuit board populated with a plurality of conductive lines;

a layer of adhesive over the flexible circuit board, the layer of adhesive defining an opening over at least one area of the flexible circuit board, the at least one area being electrically-conductive;

an electrically insulating layer between the adhesive layer and the flexible circuit board, wherein the electrically insulating layer includes an opening approximately located under the opening of the adhesive layer, the opening of the electrically insulating layer approximating the size of the opening of the adhesive layer;

an electrically conducting layer between the adhesive and the electrically insulating layer, wherein the electrically conducting layer includes an opening approximately located under the opening of the adhesive, the opening of the electrically conducting layer approximating the size of the opening of the adhesive;

electrically-conductive material located in the openings in the adhesive layer and the electrically insulating layer, wherein the electrically-conductive material is disposed over and adjacent to the at least one area of the flexible circuit board; and

a metal stiffener adhered to the structure by the adhesive layer and electrically connected to the at least one area of the flexible circuit board by contact with the electrically-conductive material.

13. The structure according to claim 12 , wherein the adhesive is a thermal set adhesive tape.

14. The structure according to claim 12 , wherein the stiffener approximately covers the layer of adhesive.

15. The structure according to claim 12 , wherein pressure and heat are used to adhere the adhesive to the electrical insulating layer and the metal stiffener.

16. The structure according to claim 1 , wherein the stiffener approximately covers the first adhesive.

17. A structure for providing rigidity to an area of less than all of the area of a flexible substrate, the structure comprising:

a first adhesive over a certain area of the flexible substrate, the first adhesive having an opening over an electrical conducting portion of the flexible substrate;

an electrically insulating layer between the first adhesive and the flexible substrate, wherein the electrically insulating layer includes an opening approximately located under the opening of the first adhesive, the opening of the electrically insulating layer approximating the size of the opening of the first adhesive;

an electrically conducting layer between the first adhesive and the electrically insulating layer, wherein the electrically conducting layer includes an opening approximately located under the opening of the first adhesive, the opening of the electrically conducting layer approximating the size of the opening of the first adhesive;

a second adhesive within a cavity defined by the openings of the first adhesive, the electrically insulating layer, and the electrically conducting layer, wherein the second adhesive is electrically conducting, and wherein the second adhesive is disposed over and adjacent to the electrically conducting portion of the flexible substrate; and

a stiffener over the first and the second adhesive.