Catalyzed metal foil and uses thereof
Systems, methods, and devices related to catalyzed metal foils are disclosed. Contemplated metal foils have a bottom surface, preferably roughened to Ra of at least 0.1 μm, bearing a catalyst material. The metal foils are etchable, typically of aluminum or derivative thereof, and is less than 500 μm thick. Methods and systems for forming circuits from catalyzed metal foils are also disclosed. The catalyst material bearing surface of the metal foil is applied to a substrate and laminated, in some embodiments with a thermoset resin or thermoplastic resin therebetween or an organic material first coating the catalytic material. The metal foil is removed to expose the catalyst material, and a conductor is plated to the catalyst material.
1. A method of forming an electrical circuit comprising a substrate using a metal foil, the method comprising:
laminating a film to a surface of the substrate;
laminating a surface of the metal foil to the film;
removing the metal foil to expose a portion of the film or substrate; and
depositing a first conductor to the portion of the film or substrate;
wherein at least one of the film or substrate or metal foil is treated with a dry chemical treatment, wherein the dry chemical treatment comprises a corona discharge, or an electron beam;
wherein the laminating surface of the metal foil is roughened by chemical etching to form an average roughness (Ra) between 0.1 μm or more to 0.5 μm or less.
2. The method of claim 1 , wherein the film is partially or fully cured.
3. The method of claim 1 , wherein the film is partially or fully cured before the step of removing the metal foil.
4. The method of claim 1 , further comprising the step of treating the film or substrate with a chemical.
5. The method of claim 4 , wherein the chemical is selected from the group consisting of an oxidizer, a solution of permanganate salt, a solution of alkali metal hydroxide, a solution of alkali earth metal hydroxide.
6. The method of claim 4 , wherein the step of laminating the surface of the metal foil to the film occurs after the step of treating the film or substrate with the chemical.
7. The method of claim 1 , further comprising the step of treating the film or substrate with a chemical after the step of removing the metal foil.
8. The method of claim 1 , wherein the film is a bonding film.
9. The method of claim 8 , wherein the bonding film is selected from the group comprising a B-stage resin sheet, a reinforced B-stage resin sheet, or a prepreg.
10. The method of claim 1 , further comprising the step of applying a catalyst precursor to the film or substrate and activating the catalyst precursor to a catalyst before the step of depositing the first conductor to the portion of the film or substrate.
11. The method of claim 1 , wherein the surface of the metal foil bears a catalyst or a catalyst precursor.
12. The method of claim 1 , wherein the surface of the metal foil bears a catalyst or a catalyst precursor before the step of laminating the surface of the metal foil to the film.
13. The method of claim 11 , wherein the catalyst or catalyst precursor remains on the film or substrate after the step of removing the metal foil.
14. The method of claim 11 , further comprising the step of activating the catalyst precursor before depositing the first conductor.
15. The method of claim 10 or 11 , wherein the step of depositing the first conductor comprises electroless deposition of the first conductor to the catalyst.
16. The method of claim 1 , further comprising the step of electrolytically depositing a second conductor on the first conductor.
17. The method of claim 1 , wherein the metal foil includes at least one of aluminum, anodized aluminum, copper, tin, or alloys thereof.
18. The method of claim 1 , wherein the step of removing the metal foil comprises etching the metal foil.