EP3699321A1

EP3699321A1 - Method of forming copper metal layer on non-metallic material

Info

Publication number: EP3699321A1
Application number: EP19157906.9A
Authority: EP
Inventors: Kuanlin KU; Jia-Cing Chen; Kuo-Hsin Chang; Chung- Ping Lai
Original assignee: BGT Materials Ltd
Current assignee: BGT Materials Ltd
Priority date: 2019-02-19
Filing date: 2019-02-19
Publication date: 2020-08-26

Abstract

A method of forming a copper metal layer (30) on a non-metallic material (20) contains: a. providing a carbon-based electroless-plating inks (10); b. spraying the carbon-based electroless-plating inks (10) on the non-metallic material (20); c. dry spraying the carbon-based electroless-plating inks (10) on the non-metallic material (20); and d. dipping the non-metallic material (20) on which the carbon-based electroless-plating inks (10) dry sprayed in an electroless plating solution. Thereby, the copper metal layer (30) is formed on the carbon-based electroless-plating inks (10) of the non-metallic material (20).

Description

FIELD OF THE INVENTION

The present invention relates to a method of forming copper metal layer on a non-metallic material by which the copper metal layer is formed on a variety of non-metallic materials at a low cost, quickly, and environmentally friendly.

BACKGROUND OF THE INVENTION

A method of plating non-metallic material contains steps of: surface pretreating and metal plating, such as cleaning, etching, sensitizing, activating, and accelerating. The strong oxidants (chromium trioxide) and sulfuric acid mixture are applied for surface roughness to obtain mechanical adhesion and to produce pores for adhering positions of a metal plate and a substrate.
The non-metallic material is a mixture of chromium trioxide, sulfuric acid, and water. Alternatively, the non-metallic material is a mixture of inorganic substance and phosphate. However, in producing the mixture of the non-metallic material, it is easy to cause toxic carcinogen, such as hexavalent chromium. Furthermore, the hexavalent chromium causes environmental pollution.
Furthermore, electroless plating, also known as chemical or auto-catalytic plating, is a non-galvanic plating method that involves several simultaneous reactions in an aqueous solution, which occur without the use of external electrical power. It is mainly different from electroplating by not using external electrical power.
In the manufacture of printed circuit boards, electroless plating is used to form the conductive part of plated through holes. The non-conductive part is treated with palladium catalyst and then made conductive by electroless copper plating.
Stable catalysts for electroless metallization is disclosed in EP 2559486A1 , the catalysts include nanoparticles of catalytic metal and cellulose or cellulose derivatives. The catalysts are used in electroless metal plating. The catalysts are free of tin. In 2007, a report is disclosed in [Science 318 (2007) 426] regarding a electroless plating adapted for copper or silver, wherein a non-metallic catalyst (such as polydopamine) is employed in the electroless plating.
EP 2712885A1 taught a method for forming a polymerized film on a surface of a non-conductive material and subsequently forming an electroless metal plating film on the surface is described. The method includes the step of contacting the surface of the material with a solution including (A) an amine compound having at least two functional groups, where at least one of the functional groups is an amino group, and (B) an aromatic compound having at least one hydroxyl group on the aromatic ring. However, it takes 4-24 hours in polymerization.
US20160168715A1 discloses that 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. But this method takes 24 hours in polymerization. Furthermore, a PH range of dopamine in polymerization is 6.5 to 9.5, thus reducing self - polymerization rate of dopamine.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a method of forming copper metal layer on a non-metallic material by which the copper metal layer is formed on a variety of non-metallic materials at a low cost, quickly, and environmentally friendly.
To obtain above-mentioned objectives, a method of forming copper metal layer on a non-metallic material provided by the present invention contains steps:

a. providing a carbon-based electroless-plating inks;
b. spraying the carbon-based electroless-plating inks on the non-metallic material;
c. dry spraying the carbon-based electroless-plating inks on the non-metallic material; and
d. dipping the non-metallic material on which the carbon-based electroless-plating inks dry sprayed in an electroless plating solution so as to form the copper metal layer on the carbon-based electroless-plating inks of the non-metallic material.

Preferably, the non-metallic material is any one of plastic, ceramic, wood, glass, and cloth.
Preferably, the carbon-based electroless-plating inks are a mixture of functional carbon powder material, a dispersant, a thicker, and a solvent
Preferably, the functional carbon powder material consists of oxygen-functional carbon powders, an oxygen content of the oxygen-functional carbon powders is 5 wt% to 50 wt% of the oxygen-functional carbon powders.
Preferably, a content of the oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks is 0.5 wt% to 30 wt% of the oxygen-functional carbon powders, a content of the dispersant is 0.05 wt% to 20 wt% of the mixture of the carbon-based electroless-plating inks, and a content of the solvent is 30 wt% to 90 wt% of the mixture of the carbon-based electroless-plating inks.
Preferably, the oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks are any one of nitrogen (N), sulfur (S), boron (B), fluorine (F), phosphorus (P), and a mixture of nitrogen, sulfur, boron, fluorine, and phosphorus, wherein a content of the oxygen-functional carbon powders is 1 wt% to 20 wt% of the functional carbon powder material.
Preferably, the oxygen-functional carbon powders are oxide consisting of any one of graphene, graphite, carbon nanotubes, carbon black, and activated carbon.
Preferably, the carbon-based electroless-plating inks further consist of adhesive made any one of polymer, resin, and binder or a mixture of the polymer, the resin, and the binder, wherein a content of the adhesive is 0.1 wt% to 30 wt% of the carbon-based electroless-plating inks.
Preferably, the dispersant is ionic dispersant or nonionic dispersant, and the solvent is any one of organic solvent, inorganic solvent, and aqueous solvent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a method of forming a copper metal layer on a non-metallic material according to the present invention.
FIG. 2-1 is a cross sectional view showing the copper metal layer on the non-metallic material according to the present invention.
FIG. 2-2 is another cross sectional view showing the copper metal layer on the non-metallic material according to the present invention.
FIG. 3A is a schematic view showing a sample A of a first embodiment of the present invention.
FIG. 3B is a schematic view showing a sample B of the first embodiment of the present invention.
FIG. 4A is a schematic view showing a sample A of a second embodiment of the present invention.
FIG. 4B is a schematic view showing a sample B of the second embodiment of the present invention.
FIG. 5A is a schematic view showing a sample A of a third embodiment of the present invention.
FIG. 5B is a schematic view showing a sample B of the third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1, a method of forming a copper metal layer on a non-metallic material according to the present invention comprises steps:

a. providing a carbon-based electroless-plating inks 10;
b. spraying or printing the carbon-based electroless-plating inks 10 on the non-metallic material 20, as shown in FIG. 2-1, wherein the non-metallic material 20 is any one of plastic, ceramic, wood, glass, and cloth;
c. dry spraying the carbon-based electroless-plating inks 10 on the non-metallic material 20; and
d. dipping the non-metallic material 20 on which the carbon-based electroless-plating inks 10 dry sprayed in an electroless plating solution so as to form a copper metal layer 30 on the carbon-based electroless-plating inks 10 of the non-metallic material 20, as shown in FIG. 2-2.

Preferably, the carbon-based electroless-plating inks 10 are a mixture of functional carbon powder material, a dispersant, a thicker, and a solvent. Preferably, the functional carbon powder material consists of oxygen-functional carbon powders, wherein the oxygen-functional carbon powders are oxide consisting of any one of graphene, graphite, carbon nanotubes, carbon black, and activated carbon. An oxygen content of the oxygen-functional carbon powders is 5 wt% to 50 wt% of the oxygen-functional carbon powders.
A content of the oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks is 0.5 wt% to 30 wt% of the oxygen-functional carbon powders.
A content of the dispersant is 0.05 wt% to 20 wt% of the mixture of the carbon-based electroless-plating inks, wherein the dispersant is ionic dispersant or nonionic dispersant.
The solvent is any one of organic solvent, inorganic solvent, and aqueous solvent, and a content of the solvent is 30 wt% to 90 wt% of the mixture of the carbon-based electroless-plating inks.
The oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks are any one of nitrogen (N), sulfur (S), boron (B), fluorine (F), phosphorus (P), and a mixture of nitrogen, sulfur, boron, fluorine, and phosphorus. A content of the oxygen-functional carbon powders is 1 wt% to 20 wt% of the functional carbon powder material.
Preferably, the carbon-based electroless-plating inks 10 further consist of adhesive made any one of polymer, resin, and binder or a mixture of the polymer, the resin, and the binder. A content of the adhesive is 0.1 wt% to 30 wt% of the carbon-based electroless-plating inks 10. Preferably, when the adhesive is made of the polymer or the resin, the binder is added with the polymer or the resin. Preferably, when the oxygen-functional carbon powders are graphene flakes or graphene oxides, the adhesive is not the polymer or the resin. A content of the thicker is 0.01 wt% to 10 wt% of the carbon-based electroless-plating inks 10.
Referring to FIG. 3A, in a first sample A of a first embodiment, the carbon-based electroless-plating inks 10 are baked in a temperature of 100 °C for 20 minutes, and the carbon-based electroless-plating inks 10 are plating bathed in formaldehyde-based electroless plating solution in a temperature of 50 °C to 70 °C for 30 minutes to 120 minutes, thus obtaining copper deposition on the carbon-based electroless-plating inks 10, as shown in a sample B of the first embodiment of FIG. 3B.
Referring to FIG. 4A, in a first sample A of a second embodiment, the non-metallic material 20 is the ceramic, the carbon-based electroless-plating inks 10 are sprayed on the non-metallic material 20, the non-metallic material 20 on which the carbon-based electroless-plating inks 10 are baked in a temperature 100 °C for 20 minutes, and the non-metallic material 20 are plating bathed in formaldehyde-based electroless plating solution in a temperature of 50 °C to 70 °C for 30 minutes to 120 minutes, thus obtaining even copper deposition on the carbon-based electroless-plating inks 10, as shown in a sample B of the second embodiment of FIG. 4B.
Referring to FIG. 5A, in a first sample A of a third embodiment, the non-metallic material 20 is the wood, the carbon-based electroless-plating inks 10 are sprayed on the non-metallic material 20, the non-metallic material 20 on which the carbon-based electroless-plating inks 10 are baked in a temperature 100 °C for 20 minutes, and the non-metallic material 20 are plating bathed in formaldehyde-based electroless plating solution in a temperature of 50 °C to 70 °C for 30 minutes to 120 minutes, thus obtaining even copper deposition on the carbon-based electroless-plating inks 10, as shown in a sample B of the third embodiment of the second embodiment of FIG. 5B.
Thereby, the copper metal layer is formed on a variety of non-metallic materials at a low cost, quickly, and environmentally friendly.
While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments which do not depart from the spirit and scope of the invention.

Claims

A method of forming a copper metal layer (30) on a non-metallic material (20) comprising:
a. providing a carbon-based electroless-plating inks (10);

b. spraying the carbon-based electroless-plating inks (10) on the non-metallic material (20);

c. dry spraying the carbon-based electroless-plating inks (10) on the non-metallic material (20); and

d. dipping the non-metallic material (20) on which the carbon-based electroless-plating inks (10) dry sprayed in an electroless plating solution so as to form the copper metal layer (30) on the carbon-based electroless-plating inks (10) of the non-metallic material (20).
The method as claimed in claim 1, wherein the non-metallic material (20) is any one of plastic, ceramic, wood, glass, and cloth.
The method as claimed in claim 1, wherein the carbon-based electroless-plating inks (10) are a mixture of functional carbon powder material, a dispersant, a thicker, and a solvent
The method as claimed in claim 3, wherein the functional carbon powder material consists of oxygen-functional carbon powders, an oxygen content of the oxygen-functional carbon powders is 5 wt% to 50 wt% of the oxygen-functional carbon powders.
The method as claimed in claim 4, wherein a content of the oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks (10) is 0.5 wt% to 30 wt% of the oxygen-functional carbon powders, a content of the dispersant is 0.05 wt% to 20 wt% of the mixture of the carbon-based electroless-plating inks (10), and a content of the solvent is 30 wt% to 90 wt% of the mixture of the carbon-based electroless-plating inks (10).
The method as claimed in claim 3, wherein the oxygen-functional carbon powders of the mixture of the carbon-based electroless-plating inks (10) are any one of nitrogen (N), sulfur (S), boron (B), fluorine (F), phosphorus (P), and a mixture of nitrogen, sulfur, boron, fluorine, and phosphorus, wherein a content of the oxygen-functional carbon powders is 1 wt% to 20 wt% of the functional carbon powder material.
The method as claimed in claim 4, wherein the oxygen-functional carbon powders are oxide consisting of any one of graphene, graphite, carbon nanotubes, carbon black, and activated carbon.
The method as claimed in claim 3, wherein the carbon-based electroless-plating inks (10) further consist of adhesive made any one of polymer, resin, and binder or a mixture of the polymer, the resin, and the binder, wherein a content of the adhesive is 0.1 wt% to 30 wt% of the carbon-based electroless-plating inks (10).
The method as claimed in claim 3, wherein the dispersant is ionic dispersant or nonionic dispersant, and the solvent is any one of organic solvent, inorganic solvent, and aqueous solvent.