Patterning of graphene circuits on flexible substrates
A process for forming a graphene circuit pattern on an object is described. A graphene layer is grown on a metal foil. A bonding layer is formed on a protective film and a surface of the bonding layer is roughened. The graphene layer is transferred onto the roughened surface of the bonding layer. The protective film is removed and the bonding layer is laminated to a first core dielectric substrate. The metal foil is etched away. Thereafter the graphene layer is etched using oxygen plasma etching to form graphene circuits on the first core dielectric substrate. The first core dielectric substrate having graphene circuits thereon is bonded together with a second core dielectric substrate wherein the graphene circuits are on a side facing the second core dielectric substrate wherein an air gap is left there between.
1. A method for forming a graphene circuit board comprising:
growing a graphene layer on a metal foil;
laminating a bonding film onto a first core dielectric substrate;
roughening a surface of said bonding film;
transferring said graphene layer onto roughened said surface of said bonding film;
thereafter etching away said metal foil;
thereafter oxygen plasma etching said graphene layer to form graphene circuits on said first core dielectric substrate; and
thereafter bonding together said first core dielectric substrate having said graphene circuits thereon with a second core dielectric substrate wherein said graphene circuits are on a side facing said second core dielectric substrate and wherein an air gap is left therebetween.
2. The method according to claim 1 wherein said bonding film comprises a thermoset adhesive film reinforced with fibers.
3. The method according to claim 1 wherein said roughening said surface of said bonding film comprises treating said surface with potassium permanganate.
4. The method according to claim 1 wherein said second core dielectric substrate has graphene patterns formed thereon facing said first core dielectric substrate.
5. The method according to claim 1 said second core dielectric substrate has a conductive layer on a side facing said first core dielectric substrate wherein said conductive layer comprises Copper, Gold, TiW, Silver, Palladium, or Aluminum.
6. The method according to claim 1 wherein said graphene patterns are electrodes or electrolytes.
7. The method according to claim 1 wherein said first and second core dielectric substrates comprise Polyimide (PI), Liquid Crystal Polymer (LCP), polyester (PET), polyethylene-naphthalate (PEN), laminates of epoxies or Bismaleimide-Triazine resin (BT), Teflon, modified Teflon, ceramic, or Cyclo-olefin Polymers (COP).
8. The method according to claim 1 wherein at least one of said first and second core dielectric substrates further comprises one or more conductive metal layers on a side of said substrate opposite to said side having said graphene patterns thereon, wherein said conductive metal layers comprise copper (Cu), Silver (Ag), Palladium (Pd), Aluminium (Al), Titanium-Tungsten (TiW), and/or Gold (Au).
9. The method according to claim 1 wherein each of said first and second core dielectric substrates has a thickness of between about 2 and 200 μm and wherein said graphene patterns have a thickness of between about 0.3 and 3 nm.
10. The method according to claim 1 wherein said bonding of said first and second core substrates uses pressure-sensitive adhesive, thermal-sensitive adhesive, conductive epoxy, or non-conductive epoxy.
11. A method for forming a graphene circuit board comprising:
growing a graphene layer on a metal foil;
forming a bonding layer on a protective film and roughening a surface of said bonding layer;
transferring said graphene layer onto roughened said surface of said bonding layer;
thereafter removing said protective film and laminating said bonding layer to a first core dielectric substrate;
thereafter etching away said metal foil;
thereafter oxygen plasma etching said graphene layer to form graphene circuits on said first core dielectric substrate; and
thereafter bonding together said first core dielectric substrate having said graphene circuits thereon with a second core dielectric substrate wherein said graphene circuits are on a side facing said second core dielectric substrate and wherein an air gap is left therebetween.
12. The method according to claim 11 wherein said bonding layer comprises a thermoset adhesive film reinforced with fibers.
13. The method according to claim 11 wherein said roughening said surface of said bonding film comprises treating said surface with potassium permanganate.
14. The method according to claim 11 wherein said second core dielectric substrate has graphene patterns formed thereon facing said first core dielectric substrate.
15. The method according to claim 11 said second core dielectric substrate has a conductive layer on a side facing said first core dielectric substrate wherein said conductive layer comprises Copper, Gold, TiW, Silver, Palladium, or Aluminum.
16. The method according to claim 11 wherein said graphene patterns are electrodes or electrolytes.
17. The method according to claim 11 wherein said first and second core dielectric substrates comprise Polyimide (PI), Liquid Crystal Polymer (LCP), polyester (PET), polyethylene-naphthalate (PEN), laminates of epoxies or Bismaleimide-Triazine resin (BT), Teflon, modified Teflon, ceramic, or Cyclo-olefin Polymers (COP).
18. The method according to claim 11 wherein at least one of said first and second core dielectric substrates further comprises one or more conductive metal layers on a side of said substrate opposite to said side having said graphene patterns thereon, wherein said conductive metal layers comprise copper (Cu), Silver (Ag), Palladium (Pd), Aluminium (Al), Titanium-Tungsten (TiW), and/or Gold (Au).
19. The method according to claim 11 wherein each of said first and second core dielectric substrates has a thickness of between about 2 and 200 μm and wherein said graphene patterns have a thickness of between about 0.3 and 3 nm.
20. The method according to claim 11 wherein said bonding of said first and second core substrates uses pressure-sensitive adhesive, thermal-sensitive adhesive, conductive epoxy, or non-conductive epoxy.