Methods of Treating a Surface to Promote Metal Plating and Devices Formed

Abstract

Embodiments of the present invention provide methods of treating a surface of a substrate. In one particular aspect, embodiments of the present invention provide methods of treating a surface of a substrate that promote binding of one or more metal elements to the surface. According to some embodiments of the invention, films are formed on any conducting, semiconductive or non-conductive surface, by thermal reaction of molecules containing reactive groups in an organic solvent or in aqueous solution. The thermal reaction may be produced under a variety of conditions. In another aspect, the present invention provides a printed circuit board, comprising: at least one substrate; a layer of organic molecules attached to the at least one substrate; and a metal layer atop said layer of organic molecules.

1 . A method of electroplating a surface of a substrate, comprising the steps of:
 contacting the surface with one or more organic molecules, said organic molecules being configured to promote metal binding;   heating the one or more organic molecules and the substrate to a temperature of at least 25° C. wherein the organic molecules form a layer of the organic molecules on the surface of the substrate;   placing the substrate in an electroless plating bath wherein metal ions in said plating bath are reduced and bind to said one or more organic molecules to form a metallic layer on the surface of the substrate.   
     
     
         2 . The method of  claim 1  further comprising:
 forming a metal seed layer atop the layer of organic molecules prior to placing the substrate in an electroless plating bath, said metal seed layer attaching to the one or more organic molecules.   
     
     
         3 . The method of  claim 1  wherein the one or more organic molecules are selectively formed on desired regions of the surface, and the metallic layer is formed atop said desired regions. 
     
     
         4 . The method of  claim 1  wherein the one or more organic molecules is a surface active moiety. 
     
     
         5 . The method of  claim 4  wherein said surface active moiety is selected from the group consisting of a macrocyclic proligand, a macrocyclic complex, a sandwich coordination complex and polymers thereof. 
     
     
         6 . The method of  claim 4  wherein said surface active moiety is a porphyrin. 
     
     
         7 . The method of  claim 1  wherein the one or more organic molecules bear at least one attachment group comprised of an aryl functional group and/or an alkyl attachment group. 
     
     
         8 . The method of  claim 7  wherein the aryl functional group is comprised of a functional group selected from any one or more of: bromo, iodo, hydroxy, ether, hydroxymethyl, formyl, bromomethyl, vinyl, allyl, S-acetylthiomethyl, Se-acetylselenomethyl, ethylnyl, 2-(trimethylsilyl)ethynyl, mercapto, mercaptomethyl, 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl, and dihydroxyphosphoryl. 
     
     
         9 . The method of  claim 7  wherein the alkyl attachment group comprises a functional group selected from any one or more of: bromo, iodo, hydroxy, ether, formyl, vinyl, mercapto, selenyl, S-acetylthio, Se-acetylseleno, ethynyl, 2-(trimethylsilyl)ethynyl, 4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl, and dihydroxyphosphoryl. 
     
     
         10 . The method of  claim 7  wherein the at least one attachment group is comprised of any one or more of: amines, alcohols, ethers, other nucleophile, phenyl ethynes, phenyl allylic groups, phosphonates and combinations thereof. 
     
     
         11 . The method of  claim 2  wherein the one or more organic molecules further comprise one or more binding groups comprised of alcohols, ethers, other nucleophiles, phenyl ethynes, phenyl allylic groups, phosphonates, amines, pyridine; pyrazine; isonicotinamide; imidazole; bipyridine and substituted derivatives of bipyridine; terpyridine and substituted derivatives; nitriles, isonitriles, thiocyanates, phenanthrolines, substituted derivatives of phenanthrolines, oxygen, sulfur, phosphorus and nitrogen-donating ligands and combinations thereof. 
     
     
         12 . The method of  claim 1  wherein the one or more organic molecules is comprised a thermally stable base bearing one or more binding groups configured to bind the molecules of interest and one or more attachment groups configured to attach to the organic molecule to the surface. 
     
     
         13 . The method of  claim 1  wherein the substrate is comprised of any one of more of: PCB substrates, polymer, ceramic, carbon, epoxy, glass reinforced epoxy, phenol, polyimide resines, glass reinforced polyimide, cyanate, esters, Teflon, Group III-IV elements, and mixtures thereof. 
     
     
         14 . The method of  claim 1  wherein the substrate is comprised of any one of more of: a planar substrate, curved substrate, non-planar substrate, etched substrate, or deposited domain on another substrate. 
     
     
         15 . The method of  claim 1  wherein said contacting step comprises any one or more of: dipping, drip-coating, drop-coating, spin-coating, spraying, ink-jet printing, contact printing, vapor deposition, plasma assisted vapor deposition, sputtering, molecular beam epitaxy, and combinations thereof. 
     
     
         16 . The method of  claim 1  wherein heating the substrate is carried out in any one or more of: an oven, hot plate, CVD device, furnace, rapid thermal heating furnace, MBE device, and combinations thereof. 
     
     
         17 . The method of  claim 1  further comprising:
 applying a solvent rinse to the surface prior to the contacting step.   
     
     
         18 . The method of  claim 1  further comprising:
 cleaning the surface of the substrate subsequent to the heating step.   
     
     
         19 . The method of  claim 18  wherein said cleaning step comprises any one or more of: washing, rinsing, descuming or desmearing. 
     
     
         20 . The method of  claim 16  wherein the one or more organic molecules and the substrate are heated to a temperature of at least 50° C. 
     
     
         21 . The method of  claim 1  wherein the one or more organic molecules and the substrate are heated to a temperature of at least 100° C. 
     
     
         22 . The method of  claim 1  wherein the one or more organic molecules and the substrate are heated to a temperature of at least 150° C. 
     
     
         23 . The method of  claim 1  wherein the one or more organic molecules and the substrate are heated to a temperature of up to about 400° C. 
     
     
         24 . The method of  claim 1  wherein the one or more organic molecules are carried in a solvent, dispersion, emulsion, paste, or gel. 
     
     
         25 . A method of electroplating a surface of a substrate, comprising the steps of:
 rinsing the surface with a solvent;   contacting the surface with one or more organic molecules, said organic molecules being configured to promote metal binding;   heating the one or more organic molecules and the substrate to a temperature of at least 25° C. wherein the organic molecules form a layer of the organic molecules on the surface of the substrate;   cleaning the surface of the substrate to remove excess organic molecules; and   exposing the surface to an electroless plating bath or solution wherein metal ions in said plating bath are reduced and bind to said one or more organic molecules to form a metallic layer on the surface of the substrate.   
     
     
         26 . A printed circuit board, comprising:
 at least one substrate;   a layer of organic molecules attached to the at least one substrate; and   a metal layer atop said layer of organic molecules.   
     
     
         27 . The printed circuit board of  claim 26  wherein the layer of organic molecules is comprised of molecules having a thermally stable base bearing one or more binding groups configured to bind metals and one or more attachment groups configured to attach to the organic molecule to the substrate. 
     
     
         28 . The printed circuit board of  claim 26  wherein the layer of organic molecules is comprised of a heat-resistant, metal-binding molecule selected from the group of: a porphyrin, a porphyrinic macrocycle, an expanded porphyrin, a contracted porphyrin, a linear porphyrin polymer, a porphyrinic sandwich coordination complex, or a porphyrin array. 
     
     
         29 . The printed circuit board of  claim 26  wherein the at least one substrate is comprised of any one of more of: polymer, ceramic, carbon, epoxy, glass reinforced epoxy, phenol, polyimide resines, glass reinforced polyimide, cyanate, esters, Teflon, Group III-IV elements, and mixtures thereof. 
     
     
         30 . The printed circuit board of  claim 26  further comprising at least two substrates forming a multi-layer printed circuit board. 
     
     
         31 . The printed circuit board of  claim 26  wherein said substrate comprises one or more vias formed therethrough, said vias having a layer of organic molecules formed thereon and a metal layer atop said layer of organic molecules. 
     
     
         32 . The printed circuit board of  claim 26  wherein said layer of organic molecules forms a sublayer which is functionalized with one or more elements. 
     
     
         33 . The printed circuit board of  claim 32  wherein the sublayer is functionalized by electro-deposition or electro-attaching of any one or more of: vinyl monomers, strained rings, diazonium salts, carboxylic acid salts, alkynes, Grignard derivatives, and combinations thereof. 
     
     
         34 . A method of promoting metal binding to a substrate, characterized in that: a surface of a substrate is treated with an organic molecule comprised of a thermally stable base, one or more binding groups configured to promote binding with the metal and one or more attachment groups configured to attach to the organic molecule to the surface. 
     
     
         35 . A kit for carrying out the binding of metals to a substrate, comprising:
 a container comprising a heat-resistant organic molecule derivatized with an attachment group Y and a binding group X, the binding group X promotes binding of metals; and   instructional materials teaching coupling the organic molecule to the substrate by heating the molecule and/or the surface to a temperature of at least 25 C.