Selective catalytic activation of polymeric films

• US 5,075,037 A
• Filed: 01/22/1990
• Issued: 12/24/1991
• Est. Priority Date: 11/07/1986
• Status: Expired due to Term

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Monsanto Company (Bayer AG)
• Inventors: Morgan, Albert W., Brozek, James P., O'Connor, Michael T. Jr., Capistran, James D.
• Primary Examiner(s): Ryan, Patrick J.
• Application Number:
  US07/468,509
• Time in Patent Office: 701 Days
• Field of Search: 252/501.1, 252/512, 252/514, 264/104, 156/242, 156/244.17, 427/96, 430/311
• US Class Current: 430/315
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1612 through irradiation means
• CPC Class Codes: C23C 18/1641 Organic substrates, e.g. resin, plastic
• CPC Class Codes: C23C 18/1865 Heat
• CPC Class Codes: C23C 18/1868 Radiation, e.g. UV, laser
• CPC Class Codes: C23C 18/1879 Use of metal, e.g. activation, sensitisation with noble metals
• CPC Class Codes: C23C 18/1882 Use of organic or inorganic compounds other than metals, e.g. activation, sensitisation with polymers
• CPC Class Codes: C23C 18/2033 Heat
• CPC Class Codes: C23C 18/204 Radiation, e.g. UV, laser
• CPC Class Codes: C23C 18/206 Use of metal other than noble metals and tin, e.g. activation, sensitisation with metals sensitising with tin C23C18/285, sensitising with noble metals C23C18/30
• CPC Class Codes: C23C 18/2066 Use of organic or inorganic compounds other than metals, e.g. activation, sensitisation with polymers
• CPC Class Codes: C23C 18/28 Sensitising or activating
• CPC Class Codes: C23C 18/30 Activating or accelerating or sensitising with palladium or other noble metal
• CPC Class Codes: C23C 18/405 Formaldehyde
• CPC Class Codes: H05K 3/185 by making a catalytic pattern by photo-imaging

Abstract

Catalytically inert films comprising complexes of polymer with a compound of a Group 1B or Group 8 metal at unusually low proportions of metal can be selectively activated, e.g. to provide a catalytic surface. Such films can be advantageously activatable to electroless deposition, e.g. of oxidation resistant layers of copper.

Claims

1. A solution for forming a film activatable to electroless deposition comprising

(a) a compound of a Group 1B or Group 8 metal,

(b) a polymer selected from the group consisting of polybutadiene, polychloroprene, and a polyvinyl halide wherein the polymer and metal are present in a molar ratio of monomer units to metal of less than 6000:

1 and at least about 35 to 1 for polybutadiene, at least about 28 to 1 for polychloroprene and greater than about 20 to 1 for polyvinyl halide;

(c) an organic solvent containing less than 8 percent water;

(d) a soluble chloride salt for providing solubilizing anions for said compound;

wherein films formed from said solution are catalytically inert and the concentration of metal is less than 0.1 atom percent of said metal at the film surface and higher in the interior of said film and said film is activatable to electroless deposition by exposure for up to 24 hours to UV radiation at about 7.5 milliwatt/square centimeter from a 254 nanometer wavelength mercury arc lamp at about 25 millimeters from said film surface or by exposure to heat in a 180°

C. oven for up to 5 minutes.

2. A solution of claim 1 wherein said metal is palladium.

3. A solution of claim 2 wherein said organic solvent is substantially anhydrous and comprises tetrahydrofuran, methylene chloride, cyclohexanone or mixtures thereof.

4. A solution of claim 2 wherein said soluble chloride salt comprises lithium chloride.

5. A method for preparing catalytically inert, activatable films comprising:

a. applying to a surface a solution comprising a polymer and at least one compound of a Group 1B or Group 8 metal wherein the molar ratio of monomer units of said polymer to atoms of said metal is between 6000;

1 to about 20 to 1, thereby providing a film-forming coating;

b. drying said coating to provide a catalytically inert, activatable film comprising a complex of said polymer with said compound of a Group 1B or Group 8 metal, wherein the concentration of metal is less than 0.1 atom percent of said metal at the film surface and higher in the interior of said film and said film is activatable to electroless deposition by exposure for up to 24 hours to UV radiation at about 7.5 milliwatt/square centimeter from a 254 nanometer wavelength mercury arc lamp at about 25 millimeters from said film surface or by exposure to heat in a 180°

C. oven for up to 5 minutes.

6. A method of claim 5 wherein said metal comprises palladium, platinum, iridium, rhodium, ruthenium or gold.

7. A method of claim 6 wherein said medium is substantially anhydrous.

8. A method of claim 7 wherein said applying and evaporating are conducted in a substantially anhydrous environment.

9. A method of claim 7 wherein said applying and evaporating are conducted in an environment having a relative humidity between about 30 and 80 percent.

10. A method of claim 6 wherein said polymer is a saturated and halogenated polymer, an unsaturated polymer or a vinyl polymer.

11. A method of claim 10 wherein said polymer is polyvinyl chloride and said metal is palladium.

12. A method of claim 6 further comprising delaminating the bulk of said film from said surface to provide a surface having an activatable residual layer of polymer complexed with said metal.

13. A method of claim 12 wherein said polymer is a saturated and halogenated polymer, an unsaturated polymer or a vinyl polymer.

14. A method of claim 13 wherein said polymer is polyvinyl chloride and said metal is palladium.

15. A method of providing an article that is activated to electroless deposition comprising:

a. applying to the surface of a mold a wet film comprising a solution of polymer and at least one compound of a Group 1B or Group 8 metal wherein the molar ratio of monomer units of said polymer to atoms of said metal is between about 6000 to 1 and about 20 to 1;

b. drying said wet film to provide a stable catalytically inert, activatable film comprising a complex of said polymer with said compound of a Group 1B or Group 8 metal, wherein the concentration of metal is less than 0.1 atom percent of said metal at the film surface and higher in the interior of said film and said film is activatable to electroless deposition by exposure for up to 24 hours to UV radiation at about 7.5 milliwatt/square centimeter from a 254 nanometer wavelength mercury arc lamp at about 25 millimeters from said film surface or by exposure to heat in a 180°

C. oven for up to 5 minutes;

c. contacting said film with a molten thermoplastic material, having a temperature sufficient to activate said film; and

d. solidifying said thermoplastic material to provide a laminate of solid thermoplastic material and said film having a catalytically active surface.

16. A method of claim 15 wherein said polymer is a saturated and halogenated polymer, an unsaturated polymer or a vinyl polymer.

17. A method of claim 16 wherein said polymer is polyvinyl chloride and said metal is palladium.

18. A method of claim 15 further comprising separating said laminate from said surface, wherein said surface is catalytically active to the electroless deposition of metals from solutions.

19. A method of claim 18 wherein said polymer is a saturated and halogenated polymer, an unsaturated polymer or a vinyl polymer.

20. A method of claim 19 wherein said polymer is polyvinyl chloride and said metal is palladium.

21. A method of providing electrolessly deposited metal onto selected areas of a surface comprising:

a. applying to a substrate a film-forming solution of a polymer and at least one compound of a Group 1B or Group 8 metal, wherein the molar ratio of monomer units of said polymer to atoms of said Group 1B or Group 8 metal is between about 6000 to 1 and about 20 to 1;

b. solidifying said solution to provide a catalytically inert, activatable film comprising a complex of said polymer with said compound of a Group 1B or Group 8 metal, wherein the concentration of metal is less than 0.1 atom percent of said metal at the film surface and higher in the interior of said film and said film is activatable to electroless deposition by exposure for up to 24 hours to UV radiation at about 7.5 milliwatt/square centimeter from a 254 nanometer wavelength mercury arc lamp at about 25 millimeters from said film surface or by exposure to heat in a 180°

C. oven for up to 5 minutes;

c. applying radiant energy or heat to selected areas of said film to activate said areas; and

d. contacting said film with an electroless plating solution to deposit reduced metal on said areas.

22. A method of claim 21 wherein said polymer is a saturated and halogenated polymer, an unsaturated polymer or a vinyl polymer.

23. A method of claim 22 wherein said polymer is polyvinyl chloride and said metal is palladium.