CN108697001A - A kind of preparation method of flexible electrode and/or circuit - Google Patents

Abstract

The invention provides a method for preparing flexible electrodes and/or circuits. This method uses a reducing polymer and a metal ion solution. First, the reducing polymer is patterned into a pattern of a flexible electronic circuit or electrode on a flexible substrate or smooth glass by a patterning method. After drying and stripping, it is immersed in a metal ion solution. , through the electroless plating method, the metal ions are reduced by the reducing polymer, and a uniform conductive film is formed on the surface of the flexible electronic circuit or electrode pattern, thereby making a flexible electronic circuit or electrode. Compared with the prior art, the method of the present invention is simple and easy to implement, solves the problems of substrate damage and metal film cracking caused by sintering, is beneficial to realize the "roll-to-roll" production of flexible printed circuits, and has comparative advantages in the field of flexible printed electronics. great application potential.

Description

A kind of preparation method of flexible electrode and/or circuit

technical field

The invention relates to the technical field of flexible electronics, in particular to a method for preparing flexible electrodes and/or circuits.

Background technique

Flexible electronics have the special properties of being bendable, winding, and folding, combined with high-efficiency, low-cost, and large-area manufacturing technologies, it has broad application prospects in information, energy, medical, national defense, and other fields. At present, the processing technology of flexible electronics mainly includes micro-nano processing and printing technology. Because micro-nano processing needs to go through multiple processes such as mask preparation, photolithography, exposure, development, and etching, the preparation process is complicated; while printing technology (including screen printing, extrusion coating, inkjet printing, etc.) can The conductive ink is directly printed into the required pattern, which greatly reduces the processing steps, saves materials and reduces costs.

The conductive materials of commonly used conductive inks mainly include conductive polymers, metal nanoparticles, carbon nanotubes and graphene, among which conductive polymers and metal nanoparticles are current research hotspots. This is mainly because conductive polymers have the advantages of easy dispersion and compatibility with flexible substrates, while metal nanoparticles have good electrical conductivity. But both also have their own disadvantages: conductive polymer materials have weak conductivity; metal nanoparticles are easy to agglomerate, and organic dispersants need to be added, but organic dispersants need to be removed by sintering to improve the conductivity of the material, while sintering The accompanying high temperature will damage the flexible substrate; at the same time, due to the mismatch of thermal expansion coefficient between the metal film and the flexible substrate, it will also lead to cracking of the metal film.

Contents of the invention

The present invention provides a kind of preparation method of flexible electrode and circuit, and this method utilizes reductive polymer, metal ion solution, comprises the steps:

Step 1: Preparation of Reductive Polymer Ink

The reductive polymer ink includes a reductive polymer and a solvent, wherein the reductive polymer has a reducing effect, and can reduce metal cations with a higher oxidation-reduction potential than the reductive polymer into metal simple substances.

The reducing polymer includes, but is not limited to, one or more of acrylamide hydrogel, polyaniline, polypyrrole, and the like.

The solvent includes but not limited to one or more of chloroform, tetrahydrofuran, dimethylsulfoxide, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, and the like.

Preferably, in the reducing polymer ink, the reducing polymer mass accounts for 1%-40% of the solvent mass.

Preferably, the reducing polymer ink further includes a surfactant for adjusting surface tension and solubility. The surfactants include, but are not limited to, one or more of sodium dodecylsulfonate, sodium polyphosphate, Tween 80, tributyl phosphate, sodium carboxymethylcellulose, and the like. As a further preference, in the reducing polymer ink, the mass percentage content of the surfactant is 0.1-16%.

The preparation method of the reducing polymer ink is not limited, it can be prepared by directly synthesizing the reducing polymer in liquid phase, or it can be prepared by dissolving the reducing polymer powder in a solvent.

Step 2: Pattern the reducing polymer ink on a flexible substrate or a smooth glass substrate according to the pattern of the required flexible electrodes and/or circuits to obtain flexible transition electrodes and/or circuits, which are dried from the flexible substrate or The smooth glass substrate is separated, resulting in a reducing polymer flexible transition electrode and/or circuit.

The method of patterning is not limited, including one or more of gravure printing, gravure compensation printing, extrusion coating printing, screen printing, elastic printing, inkjet printing, casting method and the like.

As a drying implementation method, the flexible transition electrode and/or circuit are left to stand for 2-48 hours at a temperature range of 20-150°C and a humidity range of 5%RH-95RH%.

The flexible substrate material is not limited, including polydimethylsiloxane (PDMS), polyethylene terephthalate (PET), polyimide film (PI), polyvinylidene fluoride film (PVDF), polytetrafluoroethylene dispersion resin (PTME), polymethyl methacrylate (PMMA), polyurethane (PU), etc. one or more.

Preferably, the flexible substrate is subjected to surface modification treatment.

The surface modification treatment method is not limited, including one or more of plasma treatment, ozone surface radiation, surfactant treatment and graft copolymerization treatment.

Step 3: The flexible transition electrode and/or circuit is immersed in the metal ion solution, and the metal cations with higher redox potential than the reducing polymer are reduced by electroless plating, forming a uniform conductive film on the surface.

The metal is not limited, and includes one or more of copper, silver, cobalt, nickel, aluminum, zinc, gold, platinum, palladium and the like.

The metal ion solution is not limited, and includes metal soluble hydrochloric acid, sulfuric acid, nitrate, chloropalladic acid or chloroauric acid and the like.

Preferably, the concentration of the metal ion solution is 50-500ppm.

Preferably, the flexible transition electrodes and/or circuits are immersed in the metal ion solution for 2-35 minutes.

The present invention uses reductive polymers and metal ion solutions. First, the reductive polymers are patterned into patterns of flexible electronic circuits or electrodes on flexible substrates or smooth glass, and then dipped in metal ion solutions after drying and peeling off. , through the electroless plating method, the metal ions are reduced by the reducing polymer, and a uniform conductive film is formed on the surface of the flexible electronic circuit or electrode pattern, thereby making a flexible electronic circuit or electrode. Compared with the prior art, it has the following beneficial effects:

(1) Compared with the photolithographic etching process of the traditional printed circuit board conductive circuit, the present invention has the advantages of simple process, material saving, pollution reduction and cost reduction.

(2) Compared with the method of preparing conductive lines with metal nanoparticle inks used in common flexible printed electronics, the present invention reduces the difficulty of ink preparation and solves the problems of substrate damage and metal film cracking caused by sintering.

(3) The present invention facilitates the realization of "roll-to-roll" production of flexible printed circuits.

Description of drawings

Fig. 1 is the photograph that the reductive polymer ink in the embodiment of the present invention 1 expands naturally into flexible film in petri dish;

Fig. 2 is the polymer figure that the reductive polymer ink in the embodiment of the present invention 2 obtains by inkjet printing;

Fig. 3 is the XPS test result of the conductive thin film prepared in Example 1 of the present invention.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way.

Example 1:

(1) In an acidic solution, polyaniline is synthesized by oxidatively polymerizing aniline with excess ammonium sulfate solution, and deprotonated with sodium hydroxide solution to obtain intrinsic polyaniline.

0.2 g of polyaniline powder was dissolved in 2 g of N-methylpyrrolidone, and vigorously stirred at 50° C. for 1 h by magnetic stirring to obtain polyaniline ink.

(2) The polyaniline ink was dropped naturally in a smooth glass petri dish, and the polyaniline film was obtained after drying. As shown in Figure 1, the polyaniline film can be bent and folded at will.

(3) the auric acid solution of preparation 100ppm; Polyaniline film is immersed in this chloroauric acid aqueous solution 30min, and metal ion is reduced, forms uniform conductive film on its surface, cleans, dries with deionized water then, obtains conductive film.

The XPS test results of the conductive thin film prepared above are shown in FIG. 3 , and the 4f peak of simple gold appears in the XPS results, indicating that gold ions are reduced to simple gold.

Example 2:

(1) In an acidic solution, polyaniline is synthesized by oxidatively polymerizing aniline with excess ammonium sulfate solution, and deprotonated with sodium hydroxide solution to obtain intrinsic polyaniline.

0.1 g of polyaniline powder was dissolved in 2 g of N-methylpyrrolidone, and vigorously stirred at 40° C. for 1 h by magnetic stirring to obtain polyaniline ink.

(2) The flexible substrate is a commercially available polyethylene terephthalate film with a thickness of 0.5 mm, and its surface is modified by oxygen plasma. The polyaniline ink is printed on the flexible substrate according to the design pattern (Ningbo Institute of Materials, Chinese Academy of Sciences) by inkjet printing, and peeled off from the flexible substrate after drying to obtain a flexible film with the design pattern printed on it. In this embodiment, as shown in FIG. 2 , after inkjet printing, a polyethylene terephthalate film printed with the logo of Ningbo Material of the Chinese Academy of Sciences was obtained.

(3) prepare 100ppm of chloric acid solution. Immerse the polyethylene terephthalate film printed with design graphics in the chloroauric acid solution for 30 minutes, the metal ions are reduced, and a uniform conductive film is formed on the surface, then rinsed with deionized water, dried, A conductive film was obtained.

The XPS test result of the conductive thin film prepared above is the same as that of Example 1, indicating that gold ions are reduced to simple gold.

The embodiments described above have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All within the scope of the principles of the present invention Any modifications and improvements made should be included within the protection scope of the present invention.

Claims (10)

1. A preparation method for flexible electrode and/or circuit, is characterized in that, comprises the steps: (1) Preparation of reducing polymer ink The reductive polymer ink includes a reductive polymer and a solvent, wherein the reductive polymer has a reducing effect, and can reduce the metal cation with a higher oxidation-reduction potential in step (3) into a metal element; (2) According to the pattern of required flexible electrodes and/or circuits, the reducing polymer ink is patterned on flexible substrates or smooth glass substrates to obtain flexible transition electrodes and/or circuits. Separation of smooth glass substrates resulting in flexible transition electrodes and/or circuits of reducing polymers; (3) The reducing polymer flexible transition electrode and/or circuit prepared in step (2) are immersed in the metal ion solution, and by electroless plating, the metal ion is reduced, and the reducing polymer flexible transition electrode and /or form a uniform conductive film on the surface of the circuit. 2. the preparation method of flexible electrode and/or circuit as claimed in claim 1, is characterized in that, in described step (1), reducing polymer comprises acrylamide hydrogel, polyaniline, polypyrrole one or several. 3. the preparation method of flexible electrode and/or circuit as claimed in claim 1, is characterized in that, in described step (1), solvent comprises chloroform, THF, dimethyl sulfoxide, N-methylpyrrolidone, di One or more of methylformamide, dimethylacetamide, etc. 4. the preparation method of flexible electrode and/or circuit as claimed in claim 1, is characterized in that, in described step (1), in reductive polymer ink, the percentage that reductive polymer quality accounts for solvent mass is 1%-40%. 5. the preparation method of flexible electrode and/or circuit as claimed in claim 1, is characterized in that, in described step (1), in reducing polymer ink, also comprises surfactant; Preferably, the surfactant includes one or more of sodium dodecylsulfonate, sodium polyphosphate, Tween 80, tributyl phosphate, and sodium carboxymethylcellulose; Preferably, in the reducing polymer ink, the mass percentage content of the surfactant is 0.1-16%. 6. The method for preparing flexible electrodes and/or circuits according to any one of claims 1-5, wherein in the step (1), the reducing polymer ink is reduced by direct synthesis of liquid phase Prepared by polymer method, or prepared by dissolving reducing polymer powder in solvent. 7. The preparation method of flexible electrodes and/or circuits according to claim 1, characterized in that, in the step (2), the patterning method includes gravure printing, gravure compensation printing, extrusion coating printing , screen printing, elastic printing, inkjet printing, casting method or one or more. 8. The preparation method of flexible electrodes and/or circuits as claimed in claim 1, 2, 3, 4, 5 or 7, characterized in that, in the described step (2), the flexible substrate material comprises polydimethyl One of based silicone, polyethylene terephthalate, polyimide film, polyvinylidene fluoride film, polytetrafluoroethylene dispersion resin, polymethyl methacrylate, polyurethane species or several; As preferably, in the described step (2), the flexible substrate is first subjected to surface modification treatment; Preferably, the surface modification treatment method includes one or more of plasma treatment, ozone surface radiation, surfactant treatment and graft copolymerization treatment. 9. The preparation method of flexible electrode and/or circuit as claimed in claim 1, is characterized in that, in described step (3), metal comprises copper, silver, cobalt, nickel, aluminum, zinc, gold, platinum, One or more of palladium; Preferably, the metal ion solution includes metal soluble hydrochloric acid, sulfuric acid, nitrate, chloropalladic acid and chloroauric acid. 10. the preparation method of flexible electrode and/or circuit as claimed in claim 1,2,3,4,5,7 or 9, is characterized in that, in described step (3), the concentration of metal ion solution is 50-500ppm; Preferably, in the step (3), the flexible transition electrodes and/or circuits are immersed in the metal ion solution for 2-35 minutes.