ELECTROLESS COPPER PLATING POLYDOPAMINE NANOPARTICLES

• US 20160168715A1
• Filed: 12/10/2015
• Published: 06/16/2016
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: IP3 2017, Series 200 of Allied Security Trust I (Allied Security Trust)
• Original Assignee: The Research Foundation for The State University of New York (State University of New York)
• Inventors: Ma, Siyuan, Liu, Liang, Bromberg, Vadim, Singler, Timothy
• Granted Patent: US 10,294,567 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B41M 3/006 Patterns of chemical products used for a specific purpose, e.g. pesticides, perfumes, adhesive patterns; use of microencapsulated material; Printing on smoking articles
• CPC Class Codes: C09D 11/10 based on artificial resins
• CPC Class Codes: C09D 11/322 Pigment inks
• CPC Class Codes: C23C 18/1607 by direct patterning
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1689 After-treatment
• CPC Class Codes: C23C 18/1851 of surfaces of non-metallic or semiconducting in organic material
• CPC Class Codes: C23C 18/1893 with use of organic or inorganic compounds other than metals, first
• CPC Class Codes: C23C 18/2006 by other methods than those of C23C18/22 - C23C18/30
• CPC Class Codes: C23C 18/2086 with use of organic or inorganic compounds other than metals, first
• CPC Class Codes: C23C 18/31 Coating with metals
• CPC Class Codes: C23C 18/40 using reducing agents
• CPC Class Codes: C23C 18/44 using reducing agents
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 1/0346 containing N
• CPC Class Codes: H05K 1/097 Inks comprising nanoparticles and specially adapted for being sintered at low temperature H05K1/095 takes precedence
• CPC Class Codes: H05K 2201/0154 Polyimide
• CPC Class Codes: H05K 2201/09236 Parallel layout
• CPC Class Codes: H05K 2203/0709 Catalytic ink or adhesive for electroless plating
• CPC Class Codes: H05K 2203/0786 Using an aqueous solution, e.g. for cleaning or during drilling of holes
• CPC Class Codes: H05K 2203/1173 : Differences in wettability, e.g. hydrophilic or hydrophobic areas
• CPC Class Codes: H05K 3/125 : by ink-jet printing
• CPC Class Codes: H05K 3/1275 : by other printing techniques, e.g. letterpress printing, intaglio printing, lithographic printing, offset printing
• CPC Class Codes: H05K 3/182 : characterised by the patterning method

Abstract

Aqueous dispersions of artificially synthesized, mussel-inspired polyopamine nanoparticles were inkjet printed on flexible polyethylene terephthalate (PET) substrates. Narrow line patterns (4 μm in width) of polydopamine resulted due to evaporatively driven transport (coffee ring effect). The printed patterns were metallized via a site-selective Cu electroless plating process at a controlled temperature (30° C.) for varied bath times. The lowest electrical resistivity value of the plated Cu lines was about 6 times greater than the bulk resistivity of Cu. This process presents an industrially viable way to fabricate Cu conductive fine patterns for flexible electronics at low temperature, and low cost.

Claims

1. A method for forming a conductive trace on a substrate wettable with a volatile liquid, comprising:

providing a suspension of nanoparticles in the volatile liquid, the nanoparticles comprising a catalyst for electroless plating;

selectively depositing the suspension of nanoparticles in the volatile liquid on the substrate in a pattern, wherein at least a portion of the substrate remains un-wet by the volatile liquid;

drying the volatile liquid, to form a pattern of nanoparticles on the substrate; and

selectively electroless plating the nanoparticles, to form a conductive metal pattern corresponding to a distribution of the formed pattern of nanoparticles.

2. The method according to claim 1, wherein the substrate comprises at least one of a polyimide sheet and glass.

3. The method according to claim 1, wherein the nanoparticles comprise polydopamine.

4. The method according to claim 1, wherein the suspension of nanoparticles is selectively deposited by a method selected from the group consisting of inkjet printing, lithography, and a pad printing process.

5. The method according to claim 1, wherein the suspension of nanoparticles is aqueous, and is selectively deposited by selectively forming hydrophobic and hydrophilic regions on the substrate, and selectively wetting the hydrophilic regions with the suspension.

6. The method according to claim 1, wherein said drying comprises evaporating the volatile liquid in the suspension at an exposed surface in air.

7. The method according to claim 1, wherein the electroless plating comprises plating the nanoparticles with at least one of silver and copper.

8. The method according to claim 1, wherein the selectively depositing the suspension of nanoparticles comprises inkjet printing a line, and said drying the volatile liquid comprises evaporation to redistribute the nanoparticles according to the coffee ring effect to induce a higher concentration of nanoparticles at the edges of the inkjet printed line and a sparse distribution of nanoparticles between the edges.

9. The method according to claim 8, wherein the electroless plating forms a pair of separated conductive traces at the edges of the inkjet printed line.

10. The method according to claim 1, wherein the electroless plating comprises electroless copper plating, resulting in at least one continuous reduced copper trace on the substrate.

11. A patterned substrate having at least one conductive trace, formed by a process comprising:

providing a substrate having a surface wettable with a volatile liquid;

selectively depositing a suspension of nanoparticles in the volatile liquid, the nanoparticles comprising a catalyst for electroless plating, in a pattern on the surface, wherein at least a portion of the substrate remains free of the suspension;

drying the volatile liquid, to form a pattern of nanoparticles on the substrate; and

selectively electroless plating the nanoparticles, to form a conductive metal pattern corresponding to the selective deposition pattern of the suspension of nanoparticles on the surface.

12. The patterned substrate according to claim 11, wherein the pattern of nanoparticles on the substrate formed after drying is inhomogeneous within the bounds of the pattern on the surface, and the conductive metal pattern is correspondingly inhomogeneous.

13. The patterned substrate according to claim 11, wherein the substrate comprises at least one of a polyimide sheet and a glass sheet.

14. The patterned substrate according to claim 11, wherein the nanoparticles comprise polydopamine.

15. The patterned substrate according to claim 11, wherein the suspension of nanoparticles is selectively deposited by a process selected from the group consisting of inkjet printing, lithography, and a pad printing process.

16. The patterned substrate according to claim 11, wherein the suspension of nanoparticles is aqueous, and is selectively deposited by selectively forming hydrophobic and hydrophilic regions on the substrate, and wetting the hydrophilic regions with the suspension.

17. The patterned substrate according to claim 11, wherein the electroless plating comprises plating the nanoparticles with at least one of silver and copper.

18. The patterned substrate according to claim 11, wherein the selectively depositing the suspension of nanoparticles comprises inkjet printing a line, and said drying the volatile liquid comprises redistributing the nanoparticles according to the coffee ring effect to induce a higher concentration of nanoparticles at the edges of the inkjet printed line and a sparse distribution of nanoparticles between the edges;

and wherein the electroless plating forms a pair of separated conductive traces at the edges of the inkjet printed line.

19. A substrate having electrically interconnecting conductive traces, comprising:

a surface wettable with an aqueous solution;

a plurality of catalytic nanoparticles deposited on the wettable surface in a pattern of parallel lines spaced by a region of sparse catalytic nanoparticle deposition; and

an electroless plating of a conductive metal selectively forming conductive traces over the parallel lines of catalytic nanoparticles, and being insulating between the respective parallel lines.

20. The substrate according to claim 19, wherein the parallel lines of catalytic nanoparticles have a distribution formed by a coffee ring effect from drying a volatile liquid from a suspension of the catalytic nanoparticles in the volatile liquid.

21. The substrate according to claim 19, wherein the surface comprises at least one of a surface of a polyimide sheet and a glass surface, the nanoparticles comprise polydopamine, and the conductive metal comprises at least one of silver and copper.

22. The substrate according to claim 19, wherein the surface wettable with an aqueous solution has selectively formed hydrophobic and hydrophilic regions on the substrate.

23. A device, comprising:

a substrate having a surface with at least one hydrophilic portion;

a parallel line pattern of deposited catalytic nanoparticles the surface, wherein the parallel line pattern comprises dense linear catalytic nanoparticle deposition regions within the hydrophilic portion, and a sparse catalytic nanoparticle deposition region between a respective pair of dense linear nanoparticle deposition regions in the hydrophilic portion; and

electrolessly plated metal selectively formed proximate to the catalytic nanoparticles, forming conductive traces over the dense linear catalytic nanoparticle deposition regions, and being essentially insulating between the respective pair of dense linear nanoparticle deposition regions.

24. The device according to claim 23, wherein the catalytic nanoparticles comprises polydopamine, and the electrolessly plated metal comprises copper.