CN114988401B

CN114988401B - Method for directly blackening graphene oxide modified by PCB

Info

Publication number: CN114988401B
Application number: CN202210530239.4A
Authority: CN
Inventors: 刘政; 潘志文; 陈伟长; 宋涛
Original assignee: Nantong Circuit Electronic Co ltd
Current assignee: Nantong Circuit Electronic Co ltd
Priority date: 2022-05-16
Filing date: 2022-05-16
Publication date: 2023-06-09
Anticipated expiration: 2042-05-16
Also published as: CN114988401A

Abstract

The invention provides a method for directly blackening a circuit board by graphene oxide, which is characterized by comprising the following steps: (1) After the circuit board is cleaned and gummed, the circuit board is put into GO-solution for a period of time, and is taken out, cleaned and dried; (2) Putting the circuit board in the step (1) into the GO+ solution for a period of time, and taking out, cleaning and drying; (3) Placing the circuit board in the step (2) into a reducing agent for reaction, and taking out, cleaning and drying; (4) And (3) electroplating the surface of the circuit board in the step (3) to obtain the graphene oxide direct blackening circuit board. With the increase of the adsorption layer number of the graphene oxide, the better the conductivity is, the time and the current power of the subsequent electroplating process are reduced, and the cost is saved.

Description

Method for directly blackening graphene oxide modified by PCB

Technical Field

The invention belongs to the technical field of printed boards, and particularly relates to a method for directly blackening graphene oxide modified by a PCB.

Background

PCB (printed circuit board), a printed wiring board, is one of the important components of the electronics industry. Almost every electronic device, as small as an electronic watch, a calculator, as large as a computer, a communication electronic device, a military weapon system, has only electronic components such as an integrated circuit, and a printed board is used for electrically interconnecting the respective components. With the continuous development of electronic technology, the demand for multi-layer high-density interconnected circuit boards is increasing, and the core problem is how to realize the electrical interconnection between the layers, namely, the hole metallization process.

The current hole metallization process mainly comprises three kinds. The first is the most used electroless copper plating method at present, mainly by a series of chemical treatment methods, a layer of copper is deposited on a non-conductive substrate, and then the purpose of electrical interconnection is achieved by thickening through a subsequent electroplating method; secondly, adsorbing conductive materials such as graphite or carbon black on a non-conductive base material, and forming a thicker copper layer in the hole by electroplating in the follow-up process; thirdly, a conductive polymer material such as thiophene, pyrrole and the like is used as a conductive material to be adsorbed on a non-conductive base material, and a copper layer is thickened through electroplating.

Specifically:

(1) The electroless copper plating method is mature, but has serious pollution and contains substances harmful to human bodies such as formaldehyde; carbon black and graphite are mostly large-particle-size particles, have poor dispersibility, are easy to settle in aqueous solution, have poor adsorption capacity and poor conductivity, and are difficult to form a compact conductive layer on a substrate; the conductive polymer material is poorer in conductivity than carbon black and the like, and is easy to crack at high temperature in the use process, so that the production control difficulty is high, and the development of the conductive polymer material is limited.

For the above reasons, it is currently desired to replace the conventional electroless copper plating process, and a relatively good conductive carbon-based material, such as graphene, is used as the conductive material adsorbed on the non-conductive substrate. The graphene is a two-dimensional crystal formed by combining benzene six-membered rings without any unstable bonds, the chemical stability is high, the surface of the graphene is in an inert state, the interaction with other solvents is weak, and strong van der Waals force exists between graphene sheets, so that aggregation is easy to occur, and therefore the graphene is difficult to dissolve in water and common organic solvents, and great difficulty is caused to further research and application of the graphene. Therefore, before graphene is used, graphene is usually required to be subjected to oxidation treatment, and the obtained graphene oxide sheet layer contains rich oxygen-containing groups, and the functional groups have strong polarity, so that the graphene oxide has good solubility in water, and convenience is brought to subsequent production.

(2) The oxygen-containing groups such as hydroxyl, carboxyl, epoxy and the like on the surface of the graphene oxide are electronegative, so that the adsorption process is similar to a chemical copper deposition method, the hole wall of the graphene oxide is positively charged after hole arrangement, and a conductive layer is formed in the hole through electrostatic adsorption with the negatively charged graphene oxide, but the graphene oxide damages the conjugated structure of the graphene due to the introduction of the oxygen groups, so that the conductivity of the graphene oxide is obviously reduced, the graphene oxide is not conductive, and the graphene oxide needs to be reduced after hole arrangement adsorption, so that the graphene with conductivity is obtained. The graphene oxide is of a sheet structure, a compact film is easily formed on the hole wall, but the thickness of the graphene oxide is thinner and is only a few nm, so that in order to avoid the defect that the film is broken and the like in the subsequent process flow to influence the conductive performance in the hole, the whole-hole adsorption process is generally required to be carried out for many times, so that the whole hole is completely covered by the graphene oxide, the conductive performance is enhanced, and the process flow and the cost are increased by repeating the whole-hole adsorption process.

(3) The positive charge of the graphene oxide is mainly realized by grafting amino groups on the graphene oxide, so that the graphene oxide is positive in solution. The most ideal method at present is to directly condense carboxyl and amino on graphene oxide, and the only byproduct is water, but the carboxyl and amino are mixed to generate ammonium salt only due to the acidity of the carboxyl and the alkalinity of the amino, so the method is not applicable. The following are common carboxyl and amino grafting methods: (1) acid chloride process; (2) a mixed anhydride process; (3) active ester process. Wherein, the acyl chloride (such as CN 201410361609.1) has a fast reaction rate, but is easy to cause racemization of alpha position of carboxylic acid, and the acylating agent can generate hydrogen sulfide, so that acid sensitive groups in the substrate are easy to be destroyed; the problem that the reaction area of the carboxylic acid and the amine is easy to generate indiscriminate in the mixed anhydride method, and the mixed anhydride can generate disproportionation reaction to generate symmetrical anhydride; the active ester method mainly comprises the steps of reacting carboxylic acid under the action of alcohol or acid to generate an ester intermediate, and then utilizing the ester intermediate and amine to generate amide, so that amino groups are grafted on graphene oxide, but the reaction is required to be carried out in toxic and harmful methylene dichloride. At present, an amide bond is prepared by a carbodiimide compound (R-N=C=N-R), wherein carbodiimide is converted into an O-acyl isourea intermediate (formula 1) and then reacts with amine to obtain a target amide bond (formula 2), but the intermediate is subjected to 1, 3-rearrangement to generate N-acyl urea (formula 3), the reaction is irreversible, and the N-acyl urea is not reacted with amine, so that the amination degree of a product is reduced.

Disclosure of Invention

Aiming at the problems, the invention provides a PCB blackening method for directly adsorbing graphene oxide without a pore-forming agent.

Based on the above problems, the invention provides a method for directly blackening graphene oxide into a circuit board, which comprises a preparation method of modified negative-charge graphene oxide and a preparation method of modified positive-charge graphene oxide.

The english full names and chinese definitions of abbreviations appearing in the present invention are listed.

PCB (printed circuit board) Printed Circuit Board

GO: oxidized graphene

GO +: positive charge graphene oxide

GO-: graphene oxide is negatively charged.

The first aspect of the invention provides a preparation method of negative-charge graphene oxide, which is characterized by comprising the following steps: (1) Adding concentrated sulfuric acid into a reaction container, adding graphite powder, persulfate and phosphorus oxide, diluting after the reaction is finished, filtering, washing and drying the solution to obtain a graphite solution; (2) Adding concentrated sulfuric acid into the graphite solution obtained in the step (1), then adding potassium permanganate, after the reaction is finished, adding water for dilution, and then adding hydrogen peroxide for reaction to obtain an intermediate solution; (3) Taking out the supernatant in the step (2), washing with an acid solution, filtering and drying the precipitate, dispersing in water, dialyzing, centrifuging and drying the dispersion liquid to obtain negative-charge graphene oxide GO-.

According to the preparation method of the negative charge graphene oxide, in the step (1), the reaction is carried out at the temperature of 0-100 ℃, preferably at the temperature of 30-100 ℃, more preferably at the temperature of 50-100 ℃, and even more preferably at the temperature of 50-80 ℃.

According to the preparation method of the negative-charge graphene oxide, the reaction time in the step (1) is 0.1-24 h, preferably 1-20 h, more preferably 1-10 h, and even more preferably 3-5 h.

According to the preparation method of the negative-charge graphene oxide, the water in the step (1) is preferably deionized water.

According to the preparation method of the negative-charge graphene oxide, the persulfate in the step (1) is one or more of potassium persulfate, sodium persulfate, ammonium persulfate and calcium persulfate.

According to the preparation method of the negative-charge graphene oxide, the phosphorus oxide in the step (1) is phosphorus pentoxide or phosphorus trioxide; preferably phosphorus pentoxide.

According to the preparation method of the negative-charge graphene oxide, in the step (1), the mass ratio of the graphite powder to the persulfate to the phosphorus oxide is 1:0.1-1, preferably 1:0.1-0.5:0.1-0.5.

According to the preparation method of the negative-charge graphene oxide, in the step (1), filtering is performed by adopting a filter membrane; the filter is preferably a glass fiber filter.

According to the preparation method of the negative-charge graphene oxide, in the step (2), potassium permanganate is added under the ice bath condition, and the reaction temperature is kept below 10 ℃.

According to the preparation method of the negative-charge graphene oxide, after the potassium permanganate in the step (2) is added, the reaction is heated, and the reaction is continued. Preferably, the temperature in the elevated temperature reaction is 20 to 100 ℃, more preferably 20 to 80 ℃, still more preferably 30 to 50 ℃, and most preferably 35 ℃. The reaction time is 0.1 to 24 hours, preferably 1 to 20 hours, more preferably 1 to 10 hours, still more preferably 1 to 3 hours.

According to the preparation method of the negative-charge graphene oxide, water adopted by the water dilution in the step (2) is preferably deionized water.

According to the preparation method of the negative-charge graphene oxide, the continuous reaction in the step (2) further comprises the steps of adding water into the system for continuous reaction, placing the system into an ice bath when the water is added, and raising the temperature after the water is added. Preferably the water is deionized water. Preferably, the temperature is from 20 to 100 ℃, more preferably from 20 to 80 ℃, even more preferably from 30 to 50 ℃, most preferably 35 ℃. The reaction time is 0.1 to 24 hours, preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours, still more preferably 0.5 to 3 hours.

According to the preparation method of the negative-charge graphene oxide, in the step (3), the acid is hydrochloric acid, sulfuric acid, nitric acid or acetic acid; the water is preferably deionized water.

According to the preparation method of the negative charge graphene oxide, the mass ratio of the raw graphite powder to the potassium permanganate to the hydrogen peroxide is 1:1-20:1-20, preferably 1:1-20:1-10, more preferably 1:2-20:1-10, and even more preferably 1:3-20:1-8.

The second aspect of the invention comprises a method for preparing modified positively charged graphene oxide, which is characterized by comprising the following steps: (1) Dispersing the negatively charged graphene oxide GO-of any one of the preceding claims into water, sonicating; (2) Adding a dehydrating agent and an inhibitor respectively, then adding amine, and fully reacting to obtain a suspension; (3) And (5) dialyzing and drying to obtain the modified positively charged graphene oxide GO+.

According to the preparation method of the modified positively charged graphene oxide, the dehydrating agent is one or more selected from DCC (N, N '-dicyclohexylcarbodiimide), DIC (N, N' -diisopropylcarbodiimide), EDC (1-ethyl- (3-dimethylaminopropyl) carbodiimide) or 1, 3-di-p-tolyl-carbodiimide.

According to the preparation method of the modified positively charged graphene oxide, the mass ratio of the dehydrating agent to GO-is 1-100:1, preferably 1-50:1, more preferably 5-50:1, and even more preferably 5-20:1.

According to the preparation method of the modified positively charged graphene oxide, the inhibitor is one or more selected from 4-dimethylaminopyridine, N-hydroxysuccinimide, 1-hydroxybenzotriazole, 1-hydroxy-7-aza-benzotriazol or ethyl 2-cyano-2- (hydroxyimine) acetate.

According to the preparation method of the modified positively charged graphene oxide, the mass ratio of the inhibitor to GO-is 0-1000:1, preferably 1-1000:1, more preferably 2-1000:1, and even more preferably 10-100:1.

According to the preparation method of the modified positively charged graphene oxide, the amine is preferably diamine, one amino group forms an amide bond with a carboxyl group in the reaction process, and one amino group is positively charged, such as ethylenediamine, butanediamine, hexamethylenediamine, octanediamine and the like, and besides, any diamine which meets the requirements falls within the protection scope of the invention. Preferably, the diamine is used in excess during use.

The third aspect of the invention comprises a method for directly blackening a circuit board by graphene oxide, which is characterized by comprising the following steps: (1) After the circuit board is cleaned and gummed, the circuit board is put into GO-solution for a period of time, and is taken out, cleaned and dried; (2) Putting the circuit board in the step (1) into the GO+ solution for a period of time, and taking out, cleaning and drying; (3) Placing the circuit board in the step (2) into a reducing agent for reaction, and taking out, cleaning and drying; (4) And (3) electroplating the surface of the circuit board in the step (3) to obtain the graphene oxide direct blackening circuit board.

According to the method for directly blackening the graphene oxide circuit board, the GO-is preferably prepared by adopting the method according to the first aspect of the invention.

According to the method for directly blackening the graphene oxide circuit board, the GO+ is preferably prepared by adopting the method according to the second aspect of the invention.

According to the method for directly blackening the circuit board by using the graphene oxide, the period of time is shorter, for example, 1-10 min, preferably 1-5 min, and more preferably 1-3 min.

According to the method for directly blackening the graphene oxide circuit board, the reaction time of the reduction reaction is 1-10 min, preferably 1-5 min, and more preferably 1-3 min.

The main contributions of the invention with respect to the prior art are the following:

(1) The conductive material selected by the invention is graphene oxide, has better conductive performance than other carbon-based materials, is of a sheet structure, and is easy to form a film after being dried. And better dispersibility can be achieved without adding other dispersing agents.

(2) The general whole pore adsorption process needs repeated whole pore adsorption for multiple times to reach higher adsorption degree, the invention does not need conventional repeated positive electricity whole pore-negative electricity adsorption-positive electricity whole pore-negative electricity adsorption and the like to form a multi-layer structure, but the step of assembling the whole pore agent layer by layer through electrostatic adsorption is reduced by changing the charge property of the graphene oxide itself, and the influence of the whole pore agent on the subsequent process is not caused because no additional whole pore agent is needed, and the purpose of conducting electricity in the pores is achieved by completing layer by layer self-assembly by means of positive and negative charge attraction of the graphene oxide itself.

(3) In the modification process of graphene oxide, a toxic solvent is not used, and a positively charged amino group is grafted on the graphene oxide based on an active ester method, so that the positively charged graphene oxide is obtained, few byproducts are generated, the amination degree of the graphene oxide is high, and the electrostatic adsorption capacity of the positively charged graphene oxide is enhanced.

(4) The hole wall directly adsorbs the positively charged graphene oxide and then adsorbs the negatively charged graphene oxide again, the whole hole is not required to be repeated in an over-adsorption process, a layer-by-layer self-assembled multilayer graphene oxide structure is formed under the action of electrostatic adsorption, and a conductive film with good compactness is formed after reduction.

Drawings

Fig. 1: the graphene oxide modification process in example 1.

Fig. 2: example 1 SEM images of graphene oxide before and after modification, where (a) is GO-, -and (b) is go+.

Fig. 3: XPS plot of modified graphene oxide (GO+) from example 1.

Fig. 4: in example 1, the graphene oxide layer in the hole of the PCB was self-assembled and electroplated.

Fig. 5: in example 1, graphene oxide layer-by-layer self-assembled in the PCB hole was subjected to SEM after electroplating.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure are clearly and completely described. It will be apparent that the described embodiments are some, but not all, of the embodiments of the present disclosure. All other embodiments, which can be made by one of ordinary skill in the art without the need for inventive faculty, are within the scope of the present disclosure, based on the described embodiments of the present disclosure.

Example 1:

(1) after adding 3mL of concentrated sulfuric acid to a round-bottomed flask, 1g of graphite powder and 0.5g of potassium persulfate, 0.5g of phosphorus pentoxide were added to the flask, respectively, and after reacting at 80℃for 5 hours, the mixture was diluted with 1L of deionized water. The graphite solution was filtered through a glass fiber filter membrane having a pore size of 1.5 μm, and then washed again with deionized water, and dried at room temperature.

(2) The pretreated graphite was added to 26mL of concentrated sulfuric acid and stirred in a flask until uniformly dispersed. Under ice bath conditions, 3g of potassium permanganate was slowly added to the flask, ensuring the reaction temperature below 10 ℃. After all additions were completed, the flask was heated to 35℃and reacted for 1h. Then the flask was placed in an ice bath, 46mL of deionized water was added to the mixture, and after continuing stirring at 35 ℃ for 0.5h, heating was stopped, and after dilution with 140mL of deionized water, 2.5mL of 30% hydrogen peroxide was added to give an bubbling bright yellow intermediate solution.

(3) The supernatant of the mixed solution was taken out, and the remaining precipitate was thoroughly washed with a 10% hydrochloric acid solution and then filtered. The resulting solid is dried and dispersed in deionized water, and the dispersion is placed in a dialysis membrane for dialysis to remove residual metal or chemical residues. And (3) carrying out centrifugal washing on the dispersion liquid for multiple times, and then drying to obtain the graphene oxide GO-.

(4) 50mg of graphene oxide powder was dispersed in 100mL of deionized water, and sonicated for 30min.

(5) 1-ethyl- (3-dimethylaminopropyl) carbodiimide was used as a dehydrating agent, 0.5g was added to the GO solution, 1.5g of 1-hydroxybenzotriazole was immediately added after vigorous stirring, and after a period of reaction, 10mL of ethylenediamine was added and the reaction was stirred at room temperature overnight.

(6) The resulting suspension was subjected to dispersion dialysis in 1L of deionized water to remove the remaining actual and byproducts and dried to give go+.

(7) GO-, cleaning the circuit board to remove the glue, putting the circuit board into 0.5 mg/mLGO-solution for 3min, taking out, cleaning and drying.

(8) GO +: and (3) putting the circuit board in the step (1) into a 0.5mg/mLGO+ solution for 3min, taking out, cleaning and drying.

(9) And (3) reduction: and (3) placing the circuit board in the step (2) into a reducing agent for reaction for 3min, and taking out, cleaning and drying.

Electroplating: and (3) electroplating the surface of the circuit board in the step (3) to obtain the graphene oxide direct blackening circuit board.

Example 2:

(2) The pretreated graphite was added to 26mL of concentrated sulfuric acid and stirred in a flask until uniformly dispersed. Under ice bath conditions, 2g of potassium permanganate was slowly added to the flask, ensuring the reaction temperature below 10 ℃. After all additions were completed, the flask was heated to 35℃and reacted for 1h. Then the flask was placed in an ice bath, 46mL of deionized water was added to the mixture, and after continuing stirring at 35 ℃ for 0.5h, heating was stopped, and after dilution with 140mL of deionized water, 2.5mL of 30% hydrogen peroxide was added to give an bubbling bright yellow intermediate solution.

Example 3:

(2) The pretreated graphite was added to 26mL of concentrated sulfuric acid and stirred in a flask until uniformly dispersed. Under ice bath conditions, 1g of potassium permanganate was slowly added to the flask, ensuring that the reaction temperature was below 10 ℃. After all additions were completed, the flask was heated to 35℃and reacted for 1h. Then the flask was placed in an ice bath, 46mL of deionized water was added to the mixture, and after continuing stirring at 35 ℃ for 0.5h, heating was stopped, and after dilution with 140mL of deionized water, 5mL of 30% hydrogen peroxide was added to obtain an bubbling bright yellow intermediate solution.

Example 4:

(7) GO-, cleaning the circuit board to remove the glue, putting the circuit board into 1 mg/mLGO-solution for 2min, taking out, cleaning and drying.

(8) GO +: and (3) putting the circuit board in the step (1) into a 1mg/mLGO+ solution for 2min, taking out, cleaning and drying.

Example 5:

(7) GO-, cleaning the circuit board to remove the glue, putting the circuit board into 2 mg/mLGO-solution for treatment for 1min, taking out, cleaning and drying.

(8) GO +: and (3) putting the circuit board in the step (1) into a 2mg/mLGO+ solution for treatment for 1min, and taking out, cleaning and drying.

Comparative example 1

(5) 1-ethyl- (3-dimethylaminopropyl) carbodiimide was used as a dehydrating agent, 0.5g was added to the GO solution, and after a period of vigorous stirring, 10mL of ethylenediamine was added and the reaction was stirred at room temperature overnight.

Comparative examples 1 to 6

The inhibitor added in the step (5) has the content of 0, 0.1, 0.5, 0.8, 1.0 and 2g respectively, and the other is the same as the above

The oxidation and amination degree of the graphene oxide is characterized by XPS, the higher the oxidation degree of the graphene oxide is, the higher the carboxyl content is, the better the water solubility is, the subsequent amination step is facilitated, the higher the amination degree is, the more positive charges are, and the self-assembly with the electrostatic adsorption layer of the negatively charged graphene oxide is easier.

The results show that:

the dosage of potassium permanganate is increased, the oxidation degree of graphene oxide is increased, oxygen-containing groups such as carboxyl groups are increased, subsequent carboxyl groups are esterified with amino groups to form amide bonds, amino groups are grafted to the surface of the graphene oxide, and the amination degree is higher; the dosage of the inhibitor is gradually increased, and the higher the amination degree of the final product is, which indicates that the inhibitor reacts with an intermediate generated in the reaction process to generate an amide bond, so that the generation of byproducts is reduced; the higher the amination degree is, the more positive charges are carried on the graphene oxide, the more electrostatic adsorption is easy to form with the negatively charged graphene oxide, the better the conductivity is, and the better the final electroplating result is.

The specific description is as follows:

in the patent CN110923771B, it is proposed that the adsorption of copper ions by graphene oxide can be enhanced by grafting a silane coupling agent onto the surface of graphene oxide, so as to improve the electroplating performance, and the modification method and the graft used in the method are different from those of the present invention, and the grafting purpose is also different. After the graphene oxide is grafted with the silane coupling agent, the surface amino groups also adsorb active metal ions and finally still present negative charges, and the graphene oxide can be adsorbed on the hole wall after hole arrangement, but the graphene oxide is changed from negative charges to positive charges after modification treatment, so that the method has an essential difference.

Finally, it should be noted that: it is apparent that the above examples are only illustrative of the present invention and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. And obvious variations or modifications thereof are contemplated as falling within the scope of the present invention.

Claims

1. The method for directly blackening the circuit board by using the graphene oxide is characterized by comprising the following steps of: (1) After the circuit board is cleaned and gummed, the circuit board is put into GO-solution for a period of time, and is taken out, cleaned and dried; (2) Putting the circuit board in the step (1) into the GO+ solution for a period of time, and taking out, cleaning and drying; (3) Placing the circuit board in the step (2) into a reducing agent for reaction, and taking out, cleaning and drying; (4) Electroplating the surface of the circuit board in the step (3) to obtain a graphene oxide direct black hole circuit board;

the preparation method of the GO-comprises the following steps: (1) Adding concentrated sulfuric acid into a reaction container, adding graphite powder, persulfate and phosphorus oxide, diluting after the reaction is finished, filtering, washing and drying the solution to obtain a graphite solution; (2) Adding concentrated sulfuric acid into the graphite solution obtained in the step (1), then adding potassium permanganate, after the reaction is finished, adding water for dilution, and then adding hydrogen peroxide for reaction to obtain an intermediate solution; (3) Taking out the supernatant in the step (2), cleaning with an acid solution, filtering and drying the precipitate, dispersing in water, dialyzing, centrifuging and drying the dispersion to obtain negative-charge graphene oxide GO-; the step (1) is to react at the temperature of 0-100 ℃; the persulfate is one or more of potassium persulfate, sodium persulfate, ammonium persulfate and calcium persulfate; the phosphorus oxide is phosphorus pentoxide or phosphorus trioxide; the filtering is filtering by adopting a filter membrane;

the preparation method of the GO+ comprises the following steps: dispersing the negative charge graphene oxide GO-into water, and carrying out ultrasonic treatment; (2) Adding a dehydrating agent and an inhibitor respectively, then adding amine, and fully reacting to obtain a suspension; (3) Dialyzing and drying to obtain modified positively charged graphene oxide GO+; the dehydrating agent is selected from one or more of N, N '-Dicyclohexylcarbodiimide (DCC), N' -Diisopropylcarbodiimide (DIC), 1-ethyl- (3-dimethylaminopropyl) carbodiimide (EDC) or 1, 3-di-p-tolylcarbodiimide; the inhibitor is selected from one or more of 4-dimethylaminopyridine, N-hydroxysuccinimide, 1-hydroxybenzotriazole, 1-hydroxy-7-aza-benzotriazole or ethyl 2-cyano-2- (hydroxyimine) acetate.

2. The method for directly blackening a circuit board by graphene oxide according to claim 1, wherein in the preparation method of the GO-, the filter membrane is a glass fiber filter membrane.

3. The method for directly blackening graphene oxide into a circuit board according to claim 1, wherein in the preparation method of the GO-, potassium permanganate is added under ice bath conditions in the step (2), and the reaction temperature is kept below 10 ℃; after the potassium permanganate is added, the reaction is heated, and the reaction is continued; the water is deionized water.

4. The method for directly blackening graphene oxide circuit board according to claim 3, wherein the continuous reaction further comprises adding water into the system to continue the reaction, placing the system in an ice bath when the water is added, and raising the temperature after the water is added.

5. A method for direct blackening graphene oxide circuit board according to any one of claims 1-3, wherein in the GO-production method, in the step (3), the acid is hydrochloric acid, sulfuric acid, nitric acid or acetic acid; the water is deionized water.

6. The method for directly blackening graphene oxide into a circuit board according to any one of claims 1-3, wherein in the preparation method of GO-, the mass ratio of the graphite powder to the potassium permanganate to the hydrogen peroxide is 1:1-20:1-20.