초록 ▼

A process is provided for fabricating metallic patterns such as resonant RF-tuned circuits on a polyolefin film such as polyethylene or polypropylene film. The film is processed under conditions such as to maintain its mechanical integrity by being passed through a solvent plasticizing bath, an etch

A process is provided for fabricating metallic patterns such as resonant RF-tuned circuits on a polyolefin film such as polyethylene or polypropylene film. The film is processed under conditions such as to maintain its mechanical integrity by being passed through a solvent plasticizing bath, an etch bath to provide attraction sites and adhesion for catalytic metal deposition, a conditioning bath to improve catalyst adhesion and a catalyst bath to deposit a catalytic metal for electroless metal deposition. A negative image is printed on the film and an electroless metal deposit followed by an electrolytic metal plate are applied to the film to produce the desired metallic patterns. Optionally, prior to the printing step, an electroless metal deposit, with or without a thin electrolytic metal plate, can be applied to the total film surface. Thereafter, a negative or positive printed image is coated on the film. When these optional steps are utilized, the electroless metal deposit, thin electrolytic metal plate and printed image are selectively removed to leave the thick electrolytic metal plate on the electroless metal deposit in the form of the desired pattern.

대표청구항 ▼

1. A process for forming a conductive circuit on a thin polyolefin film substrate which comprises passing said polyolefin film sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film, (b) a liquid etching bath adapted to provide attraction si

1. A process for forming a conductive circuit on a thin polyolefin film substrate which comprises passing said polyolefin film sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film, (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids for increased adhesion for a subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of the subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said substrate, (e) a printing step to print a negative image of the circuit on the film surface, (f) a liquid accelerator bath, to convert the catalytic metal layer to an active state to effect subsequent electroless plating of metal, (g) an electroless metal deposition bath, thereby to electrolessly deposit metal on the non-printed portion of said film, and (h) at least one electrolytic plating cell in order to increase the metal thickness to the desired level for optimum functionality of the finished circuit; said steps (a), (b), (c), (d), (e), (f), (g), and (h) being conducted so as to retain mechanical integrity of said substrate. 2. A process for forming a conductive circuit on a thin polyolefin film substrate which comprises passing said polyolefin film substrate sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film, (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids for increased adhesion of a subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said film, (e) a liquid accelerator bath adapted to convert the catalytic metal layer to an active state to effect subsequent electroless plating of metal, (f) an electroless metal deposition bath, thereby to electrolessly deposit metal on the film surface, (g) a printing step to print a negative image of the circuit on said metal plated film, (h) at least one electrolytic plating cell to selectively increase metal thickness on exposed electrolessly deposited metal, (i) a stripping bath to remove the printed ink and expose the electroless copper underneath said printed ink, and, (j) a second stripping bath to etch off the electroless metal deposit not coated with electrolytically deposited metal and thus isolate the conductive circuit patterns in the desired plated area; said steps (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) being conducted to retain mechanical integrity of said film. 3. The process of claim 2 wherein the film from step (f) is electrolytically plated on the electrolessly deposited metal prior to said printing step (g) and step (j) is conducted to remove from said film said thin film of electrolytically applied metal which has not been further plated with metal and to remove from said film electrolessly applied metal located underneath said thin film of electrolytically applied metal. 4. A process for forming a conductive circuit on a thin polyolefin film substrate, which comprises passing said polyolefin film substrate sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film, (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids, for increased adhesion for a subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said film, (e) a liquid accelerator bath adapted to convert the catalytic metal layer to an active state to effect subsequent electroless plating of metal, (f) an electroless metal deposition bath thereby to electrolessly deposit metal on the film surface, (g) a printing step to print a positive image of the circuit on said film, (h) an etching solution to remove exposed electroless metal deposit from said film, (i) a solvent stripping bath to remove said printed positive image ink from said film, and, (j) at least one electrolytic plating cell to selectively increase metal thickness on exposed electrolessly deposited metal; said steps (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) all being conducted so as to retain the mechanical integrity of the substrate. 5. The process of claim 4 wherein the film from step (f) is treated to coat the electrolessly deposited layer with a thin film of electrolytically applied metal prior to said printing step (g) and step (h) is conducted to remove from said film said thin film of electrolytically applied metal which has not been further coated with metal and to remove from said film electrolessly applied metal located underneath said thin film of electrolytically applied metal. 6. The process of any one of claims 1, 2, 3, 4, or 5 wherein said polyolefin film is polyethylene film. 7. The process of any one of claims 1, 2, 3, 4 or 5 wherein said polyolefin film is polypropylene film. 8. The process of any one of claims 1, 2, 3, 4, or 5 wherein the deposited metal is copper. 9. The process of any one of claims 1, 2, 3, 4, or 5 wherein the polyolefin film is polyethylene film and the deposited metal is copper. 10. The process of any one of claims 1, 2, 3, 4, or 5 wherein the polyolefin film is polypropylene film and the deposited metal is copper. 11. A process for forming a plurality of resonant tag circuits on a thin polyolefin film substrate, each of said resonant tag circuits including a first spiral conductive path on a first surface of said substrate and second spiral conductive path on a second surface of said substrate, said spiral conductive paths forming inductors for each of said circuits and being aligned to overlap with each other to form the desired capacitance for each of said circuits which comprises passing said polyolefin film substrate sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film substrate, (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids for increased adhesion for the subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of the subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said substrate. (e) a printing step to print a negative image of the resonant tag circuits on each of said substrate surfaces in appropriate alignment from side-to-side, (f) a liquid accelerator bath to convert the catalytic metal layer to an active state to effect subsequent electroless deposition of metal, (g) an electroless metal deposition bath, thereby to electrolessly deposit metal on the non-printed portion of said film, and, (h) at least one electrolytic plating cell in order to increase the metal thickness to the desired level for optimum functionality of the finished resonant circuit; said steps (a), (b), (c), (d), (e), (f), (g), and (h) being conducted so as to retain the mechanical integrity of said substrate. 12. The process of claim 11 wherein the film has been plated in step (g) and a small section of the circuit trace is printed with a plating resist such that the metal under this resist will not plate in subsequent plating steps resulting in a thin conductive layer forming a segment of the circuit pattern that can function as a fuse which can be rendered inoperative by means of radio frequency energy or contact with a high voltage source to overload the circuit and cause the fusible link to short and thus render the circuit inoperative. 13. The process of claims 11 or 12 wherein the film from step (d) is perforated while printing in step (e) to make at least one hole or slit in the film in an area to be plated for forming at least one through substrate electrical connection for connecting circuit traces on opposite sides of the substrate. 14. A process for forming a plurality of resonant tag circuits on a roll of a thin polyolefin film substrate, each of said resonant tag circuits including a first spiral conductive path on a first surface of said substrate and second spiral conductive path on a second surface of said substrate, said spiral conductive paths forming inductors for each of said circuits and being aligned to overlap with each other to form the desired capacitance for each of said circuits which comprises passing said thin film substrate sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film substrate. (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids for increased adhesion of a subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said substrate, (e) a liquid accelerator bath adapted to convert the deposited catalytic metal layer to an active state to effect subsequent electroless plating of metal, (f) an electroless metal deposition bath thereby to electrolessly deposit metal on the film surface, (g) a printing step to print a negative image resonant tag circuit on each of said substrate surfaces with appropriate pattern alignment and through-hole perforation, (h) at least one electrolytic plating cell to selectively increase metal thickness on exposed electrolessly deposited metal, (i) a solvent stripping bath to remove the printed ink and expose the electroless copper underneath said printed ink, and, (j) an etching bath to selectively etch off the electroless metal deposit not coated with electrolytically deposited metal and thus isolate the conductive circuit patterns in the desired plated area; said steps (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) being conducted so as to retain the mechanical integrity of said substrate. 15. The process of claim 14 wherein the film to be printed in step (g) is printed with a strippable ink, which is removed in the stripping bath in step (i), and is printed with a non-strippable ink, which cannot be removed in the stripping bath in step (i) were the metal layer under said non-strippable ink is not removed in the second stripping bath (j) and results in a thin conductive layer forming a segment of the circuit pattern that functions as a fuse. 16. The process of claims 14 or 15 wherein the film from step (f) is perforated while printing in step (g) to make at least one hole or slit in the film in an area to be printed for forming at least one through substrate electrical connection for connecting circuit traces on opposite sides of the substrate. 17. The process of claims 14 or 15 wherein the film from step (f) is treated to coat the electrolessly deposited layer with a thin film of electrolytically applied metal prior to said printing step (g) and step (j) is conducted to remove from said film said thin film of electrolytically applied metal which has not been further coated with metal and to remove from said film electrolessly applied metal located underneath said thin film of electrolytically applied metal. 18. The process of any one of claims 11, 12, 14, or 15 wherein said polyolefin film is polyethylene film. 19. The process of any one of claims 11, 12, 14, or 15 wherein said polyolefin film is polypropylene film. 20. The process of any one of claims 11, 12, 14, or 15 wherein said deposited metal is copper. 21. The process of any one of claims 11, 12, 14, or 15 wherein said polyolefin film is polyethylene film and the deposited metal is copper. 22. The process of any one of claims 11, 12, 14, or 15 wherein said polyolefin film is polypropylene film and the deposited metal is copper. 23. The process of claim 17 wherein the film to be printed in step (g) is printed with a strippable ink which is removed in the stripping bath in step (i), and a non-strippable ink, which cannot be removed in the stripping bath in step (i) where the metal layer under said non-strippable ink is not plateable, resulting in a thin conductive layer forming a segment of the circuit pattern that can function as a fuse which can be rendered inoperative by means of radio frequency energy or contact with a high voltage source to overload the circuit and cause the fusible link to short and thus render the circuit inoperative. 24. A process for forming a plurality of resonant tag circuits on a thin polyolefin film substrate, each of said resonant tag circuits including a first spiral conductive path on a first surface of said substrate and a second spiral conductive path on a second surface of said substrate, said spiral conductive paths forming inductors for each of said circuits and being aligned to overlap with each other to form the desired capacitance for each of said circuits which comprise passing said thin film substrate sequentially through: (a) a liquid plasticizing bath adapted to effect plasticizing or softening of said film, (b) a liquid etching bath adapted to provide attraction sites for subsequent catalytic metal deposition and to produce microvoids for increased adhesion for a subsequently applied metal layer, (c) a liquid conditioning bath adapted to improve adsorption of subsequently applied metal catalyst, (d) a liquid catalyst bath to effect deposition of a catalytic metal layer on said film, (e) a liquid accelerator bath adapted to convert the deposited catalytic metal layer to an active state to effect subsequent electroless plating of metal, (f) passing the substrate from step (e) through an electroless metal deposition bath thereby to electrolessly deposit metal on the film surface, (g) a printing step to print a positive image of the resonant tag circuits on each of said film surfaces, (h) an etching solution to remove exposed electroless metal deposit from said film, (i) a solvent stripping bath to remove said printed positive image ink from said film, and (j) at least one electrolytic plating cell to selectively increase metal thickness on exposed electrolessly deposited metal; said steps (a), (b), (c), (d), (e), (f), (g), (h), (i), and (j) all being conducted so as to retain the mechanical integrity of the substrate. 25. The process of claim 24 wherein the film from step (d) is perforated while printing in step (e) to make at least one hole or slit in the film in an area to be plated for forming at least one through substrate electrical connection for connecting circuit traces on opposite sides of the substrate. 26. The process of claim 24, or 23 wherein the film from step (f) is treated to coat the electrolessly deposited layer with a thin film of electrolytically applied metal prior to said printing step (g) and step (h) is conducted to remove from said film said thin film of electrolytically applied metal which has not been further coated with metal and to remove from said film electrolessly appled metal located underneath said thin film of electrolytically applied metal.