Negative imaging method for providing a patterned metal layer having high conductivity
View Patent ↗Disclosed is a method negative imaging method for making a metal pattern with high conductivity comprising providing a patterned substrate comprising a patterned catalyst layer on a base substrate by a thermal imaging method followed by plating to provide the metal pattern. The metal patterns provided are suitable for electrical devices including electromagnetic interference shielding devices and touchpad sensors.
1. A method for making a patterned metal layer having high conductivity comprising:
providing a patterned substrate comprising a patterned catalyst layer on a base substrate; said patterned substrate made by a thermal imaging method comprising:
(a) providing a thermal transfer donor comprising a base film and a catalyst transfer layer, wherein the catalyst transfer layer comprises: (i) a catalyst fraction; optionally (ii) an adhesion promoter fraction; and, optionally and independently, (iii) a polymer binder fraction;
(b) contacting the thermal transfer donor with a receiver, wherein the receiver comprises a base layer; and
(c) removing at least a portion of the catalyst transfer layer from the donor by thermal transfer to provide a patterned donor as said patterned substrate, and an exposed receiver; and
(d) removing the exposed receiver from the patterned substrate; followed by plating metal onto said patterned substrate, to provide the patterned metal layer in connectivity with the patterned catalyst layer.
2. The method of claim 1 wherein the catalyst fraction is a metal film.
3. The method of claim 1 wherein the catalyst fraction comprises one or more catalyst(s) selected from the group: (1) metal particles, including powders and colloids; (2) metal oxides; (3) organic metal complexes; (4) metal salts; (5) ceramics and other non-conductor powders coated with metal salts, metal oxides, metal complexes, metal or carbon; and (6) carbon in all conductive forms; each metal of (1) to (5) selected from the group consisting of: Ag, Cu, Au, Fe, Ni, Al, Pd, Pt, Ru, Rh, Os, Ir, Sn and alloys thereof.
4. The method of claim 1 wherein the catalyst transfer layer and patterned catalyst layer comprise an adhesion promoter fraction selected from glass frit; metal oxides; metal hydroxides and alkoxides; silicate hydroxides and alkoxides; and organic polyols.
5. The method of claim 1 wherein the catalyst transfer layer and patterned catalyst layer comprise about 1.0 to 99 wt % catalyst fraction; about 0.5 to 10 wt % adhesion promoter fraction; and about 0.5 to 98.5 wt % polymer binder fraction.
6. The method of claim 1 wherein the transferring is achieved through a laser mediated transfer and said laser has an operating wavelength of about 350 to 1500 nm.
7. The method of claim 1 wherein the thermal imaging method further comprises:
(e) heating the patterned substrate to an anneal temperature for an anneal period to provide the annealed patterned substrate; and
said plating metal comprises plating said annealed patterned substrate.
8. The method of claim 1 wherein the catalyst transfer layer and patterned catalyst layer further comprise an antireflective agent fraction.