Claims
- 1. A composite material, comprising:
a support layer; a metal foil layer having opposing first and second sides and a thickness of 15 microns or less; a bond strength enhancing agent coating said first side of said metal foil layer, said bond strength enhancing agent having a nodule height of between 0.5 micron and 2.7 microns; and a release layer effective to facilitate separation of said metal foil layer from said support layer disposed between and contacting both said support layer and said second side of said metal foil layer.
- 2. The composite material of claim 1 wherein said support layer is selected from the group consisting of stainless steel, aluminum, aluminum alloys, copper and copper alloys.
- 3. The composite material of claim 2 wherein said support layer is selected to be copper or a copper alloy.
- 4. The composite material of claim 3 wherein said support layer is selected to be wrought copper or a wrought copper alloy.
- 5. The composite material of claim 4 wherein said metal foil layer is electrolytically deposited copper.
- 6. The composite material of claim 5 wherein said metal foil layer has a thickness of between 1 micron and 6 microns.
- 7. The composite material of claim 4 wherein said bond strength enhancing agent is selected from the group consisting of copper dendrites and copper/nickel dendrites.
- 8. The composite material of claim 7 wherein said bond strength enhancing agent has an average surface roughness of 0.4 micron or less.
- 9. The composite material of claim 8 wherein said bond strength enhancing agent has a maximum height of between 1.8 microns and 2.5 microns.
- 10. The composite material of claim 8 wherein said bond strength enhancing agent has an average surface roughness of between 0.20 and 0.35 micron.
- 11. The composite material of claim 4 wherein said release layer consists essentially of chromium and at least one of an oxide of chromium and a hydroxide of chromium.
- 12. The composite material of claim 11 wherein said release layer has a thickness of between 0.001 micron and 0.03 micron.
- 13. The composite material of claim 11 wherein separation of said metal foil layer from said support layer requires a force of less than 2 pounds per inch.
- 14. The composite material of claim 13 wherein separation of said metal foil layer from said support layer requires a force of less than 1 pound per inch following exposure to a temperature of up to 300° C. for up to one hour.
- 15. The composite material of claim 14 wherein said metal foil layer is electrolytically deposited copper.
- 16. The composite material of claim 15 wherein said metal foil layer has a thickness of between 1 micron and 6 microns.
- 17. The composite material of claim 16 wherein said bond strength enhancing agent is selected from the group consisting of copper dendrites and copper/nickel dendrites.
- 18. The composite material of claim 17 wherein said bond strength enhancing agent has a maximum height of between 1.8 microns and 2.5 microns.
- 19. A circuit precursor , comprising:
a dielectric substrate; a metal foil layer having opposing first and second sides and a thickness of less than 15 microns; and a bond strength enhancing agent coating said first side of said metal foil layer and embedded in said dielectric substrate, said bond strength enhancing agent having a nodule height of between 0.5 micron and 2.7 microns.
- 20. The circuit precursor of claim 19 wherein said metal foil layer is electrolytic copper.
- 21. The circuit precursor of claim 20 wherein said bond strength enhancing agent is selected from the group consisting of copper dendrites and copper/nickel dendrites.
- 22. The circuit precursor of claim 21 wherein said bond strength enhancing agent has an average surface roughness of 0.4 micron or less.
- 23. A printed circuit panel formed from the circuit precursor of claim 22 wherein said metal foil layer is formed into conductive features electrically isolated one from another by portions of said dielectric substrate.
- 24. The printed circuit panel of claim 23 wherein said conductive features include circuit traces having a width of from 25 microns to 125 microns electrically isolated one from another by portions of said dielectric substrate having a width of from 25 microns to 100 microns.
- 25. The printed circuit panel of claim 24 wherein said dielectric substrate is a rigid epoxy.
- 26. The printed circuit panel of claim 24 wherein said dielectric substrate is a metallic core coated with a dielectric material.
CROSS REFERENCE TO RELATED APPLICATION
[0001] This patent application relates to U.S. patent application Ser. No. 09/522,544 entitled “Copper Foil Composite Including a Release Layer” by Szuchain Chen, et al. that was filed on Mar. 10, 2000. The disclosure of U.S. patent application Ser. No. 09/522,544 is incorporated by reference in its entirety herein.