Composite conductive polymers, preparation method and application thereof

Abstract

A composite conductive polymer, a preparation method thereof and application thereof are disclosed, wherein a mixed solution A is used in the preparation process of the composite conductive polymer, which comprises the following two components: (i) a strong oxidant selected from at least one of permanganate, persulfate, dichromate and perchlorate; (ii) an oxidizing agent containing a metal ion capable of being reduced to elementary substance. The preparation process is simple and easy to operate, with low cost and favorable environmental protection and the obtained composite conductive polymer containing metal in elementary form, has good film-forming property and the film thereof can completely cover the surface of the insulating substrate, with excellent electrical conductivity, which therefore can be widely used in electroplating materials and semiconductor materials and other fields.

Claims

1. A method for preparing a substrate, comprising: (a) oxidizing an insulating substrate in a mixed solution to form an oxide layer on a surface of the insulating substrate, wherein the mixed solution comprises an oxidant selected from the group consisting of permanganate, persulfate, dichromate, perchlorate, and a mixture thereof, and an oxidizing agent selected from the group consisting of Cu salt, Pd salt, Ag salt, Pt salt, or Au salt having a metal ion capable of being reduced to Cu, Pd, Ag, Pt, or Au; (b) applying on the oxidized insulating substrate a solution comprising a monomer; and (c) polymerizing the monomer to form a composite conductive polymer on the surface of the insulating substate, wherein the composite conductive polymer comprises one or more metal selected from the group consisting of Cu, Pd, Ag, Pt, Au, and mixtures thereof.

2. The method according to claim 1, wherein the monomer is at least one selected from the group consisting of pyrrole, aniline, thiophene and derivatives thereof; and the derivatives of thiophene is thiophene substituted by a C.sub.1-C.sub.10 alkyl group and/or C.sub.1-C.sub.10 alkoxy group.

3. The method according to claim 1, wherein a concentration of the monomer in the solution is from 10 mL/L to 30 mL/L.

4. The method according to claim 1, further comprising adjusting a pH of the solution to 1.8 to 2.2 using phosphoric acid or boric acid.

5. The method according to claim 1, wherein step (a) is carried out at a temperature of 60° C. to 130° C. for 5-20 min, wherein, in step (b), the solution contains a thiophene monomer having a concentration of 10 mL/L to 30 mL/L, and wherein, in step (c), the polymerization is carried out at a temperature of 15° C. to 45° C. for a time duration of 2 h to 8 h.

6. The method according to claim 1, further comprising pretreating the insulating substrate by degreasing using a degreasing liquid, washing, and plasma cleaning, wherein the degreasing liquid is at least one selected from the group consisting of an alkaline agent, a surfactant, phosphate, and a mixture of sodium hydroxide, sodium dodecylbenzenesulfonate, sodium carbonate, and trisodium phosphate at a ratio of 15-25 g/L: 0.5-2 g/L: 1-5 g/L: 3-7 g/L, wherein degreasing is carried out at 40° C.-80° C. for 3-10 min, and wherein plasma cleaning is carried out under an atmospheric pressure of 70 Pa −120 Pa and with a frequency of 80 w-100 w.

7. The method according to claim 1, wherein the mixed solution comprises: 0.2 wt % to 1 wt % of potassium permanganate, sodium permanganate, or a mixture thereof; 0.05 mol/L to 2.00 mol/L of an oxidizing agent containing Cu.sup.2+; and 5 g/L to 15 g/L of boric acid.

8. The method according to claim 1, wherein the composite conductive polymer comprises 1.00 wt %-5.00 wt % of elemental Cu.

9. A method for electroplating the substrate of claim 1, comprising: placing the substrate in a plating solution, applying an electric current, electroplating with air agitation at room temperature, and then washing and drying, wherein the plating solution comprises copper sulfate pentahydrate, concentrated sulfuric acid and chloride ion, and a concentration of the copper sulfate pentahydrate in the plating solution is from 80 g/L to 120 g/L; a concentration of the concentrated sulfuric acid in the plating solution is from 80 mL/L to 120 mL/L; a density of the applied electric current is from 2 A/dm.sup.2 to 3 A/dm.sup.2; and time for electroplating with air inflation is from 20 min to 50 min.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a physical view of an original insulating substrate;

(2) FIG. 2 is a physical view of the sample of FIG. 1 covered by a copper-containing conductive polythiophene, following the proceedings of example 1;

(3) FIG. 3 is an XRD pattern of the sample of FIG. 2;

(4) FIG. 4 is a physical view of the sample of FIG. 2 plated with copper.

DETAILED DESCRIPTION

(5) The preparation method of the present invention will be further described in detail below with reference to specific examples. It is understood that the following examples are merely illustrative of the invention and are not to be construed as limiting the scope of the invention. The technology implemented based on the above description of the present invention is intended to be within the scope of the present invention. The experimental methods used in the following examples are all conventional methods unless otherwise specified; The reagents, materials and the like used in the following examples are commercially available unless otherwise specified.

EXAMPLE 1

Preparation of Composite Conductive Polymer

(6) An insulating substrate (epoxy resin substrate, as shown in FIG. 1), after reacting with a degreasing solution (a mixture of 20 g/L sodium hydroxide, 1 g/L sodium dodecylbenzene sulfonate, 3 g/L sodium carbonate and 5 g/L of trisodium phosphate) at 50° C. for 5 minutes, was washed and dried. Then, the degreased insulating substrate was subjected to air plasma treatment at room temperature for 5 minutes, under a pressure of 90 Pa, and a frequency of 90 W. Subsequently, the treated insulating substrate was immersed in a mixture of 0.5 wt % potassium permanganate, 0.1 mol/L CuCl.sub.2.2H.sub.2O and 10 g/L boric acid at 90° C. for 10 min to form an oxide layer on the insulating substrate, which was then washed and dried. After that, the insulating substrate was immersed in a solution containing 20 mL/L of thiophene monomer for polymerization at room temperature (the solution for polymerization was purchased from Guangdong Guanghua Technology Co., Ltd., code 2303), added with 3 mL/L of phosphoric acid to adjust the pH value of the solution for polymerization, followed by reacting for 4 hours to obtain a copper-containing conductive polythiophene on the insulating substrate, and then washed and naturally dried.

(7) The copper-containing conductive polythiophene obtained by the polymerization of example 1 is shown in FIG. 2. By comparing FIG. 1 and FIG. 2, it can be seen that the copper-containing polythiophene film prepared by the embodiment of the present disclosure has good coverage property. Information about the crystal face of the elementary copper contained in the product is detected by XRD, which shows a face-centered cubic structure (see FIG. 3).

(8) The obtained copper-containing polythiophene film was subjected to a four-probe detector to measure the square resistance to characterize its electrical conductivity, and the measured square resistance is 1.83×10.sup.3Ω/Υ. In addition to this, a content of copper in the copper-containing polythiophene film was measured by XPS to be 1.68 wt %.

EXAMPLE 2

Preparation of the Substrate Plated with Copper

(9) A substrate grown with a copper-containing conductive polythiophene was immersed in a plating solution comprising 100 g/L of copper sulfate pentahydrate, 100 mL/L of concentrated sulfuric acid, and 60 mg/L of chloride ion, applied a current of 2.5 A/dm.sup.2, plated with air agitation for 30 minutes at room temperature, and taken out for washing and drying. The copper conductive layer was evenly covered on the substrate, which was as shown in FIG. 4, and it can be seen that the copper-containing conductive polythiophene film prepared by the present embodiment has excellent properties suitable for electroplating application.

EXAMPLE 3

Preparation of Composite Conductive Polymer

(10) The composite conductive polymer was prepared referring to example 1, under the same conditions as example 1 except that the concentration of CuCl.sub.2.2H.sub.2O was changed to 0.5 mol/L. Finally, a copper-containing conductive polythiophene film on the surface of the substrate was obtained.

(11) The square resistance of the film is 590Ω/Υ and the copper content of the film is 3.57 wt %.

EXAMPLE 4

Preparation of Composite Conductive Polymer

(12) The composite conductive polymer was prepared referring to example 1, under the same conditions as example 1 except that 0.1 mol/L AgNO.sub.3 was used instead of CuCl.sub.2.2H.sub.2O. Finally, a silver-containing conductive polythiophene film on the surface of the substrate was obtained.

(13) The square resistance of the film is 1.36×10.sup.3Ω/Υ and the copper content of the film is 2.02 wt %.

(14) The embodiments of the present disclosure have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and scope of the invention are intended to be included within the scope of the present invention.