A preparation method of gold-plated nickel powder

Abstract

The present application relates to a preparation method of gold-plated nickel powder, which provides a fourth mixed solution formed by mixing a gold salt, a weak acid solution and a volatile prevention additive or formed by mixing a cyanide-free gold salt and a weak acid solution, and adds the fourth nickel powder after oil removal by an alkaline solution, pickling and surface activation treatment into the fourth mixed solution to form a fifth mixed solution; the fifth mixed solution is subjected to warming and ultrasonic stirring, and the fifth mixed solution after warming and ultrasonic stirring is subjected to filtration separation to obtain the fifth nickel powder containing gold on the surface; the fifth nickel powder containing gold on the surface is subjected to cleaning and drying to obtain the gold-plated nickel powder. The present application adopts the method of adding a volatile prevention additive or using a cyanide-free gold salt for gold plating, which can effectively inhibit the volatilization of cyanide and is environmentally friendly and safe.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of microelectronic packaging, and particularly relates to a preparation method of gold-plated nickel powder. BACKGROUND

[0002] Gold has very stable chemical properties and cannot be directly oxidized by oxygen at low or high temperatures, and gold has good electrical conductivity and thermal conductivity. Nickel powder has good oxidation resistance, high electrical conductivity, and small electrical migration rate, and is widely used in catalysts, sintering activators, conductive paste, conductive adhesive, metal filtration, batteries and other products.

[0003] Package test sockets have gained wide attention due to the simplicity they provide in device testing, eliminating soldering of integrated circuits (ICs) on printed circuit boards (PCBs). Two types of sockets commonly used in electronic IC packaging are pogo-pin sockets and elastomer sockets. Compared to the pogo-pin type, the appeal of elastomer sockets mainly lies in the reduced crosstalk between pins due to their lower height. The conductors of the elastomer socket are based on gold-plated nickel powder, which compresses into a column shape during operation, thereby forming a conductive path. In high-frequency signals, when there is an alternating current or alternating electromagnetic field in the conductor, the current distribution inside the conductor is uneven, with the current concentrated in the "gold layer" part of the conductor, thereby maintaining the integrity of high-frequency signal transmission. However, the current problem is that the traditional method of preparing gold-plated nickel powder produces cyanide, which is volatile and can pollute the environment and cause harm to the human body, and the environmental protection and safety are not high.

[0004] Therefore, the application provides a preparation method of gold-plated nickel powder to solve the above technical problems. SUMMARY

[0005] In view of the above problems, the application aims to provide a preparation method of gold-plated nickel powder, which can effectively inhibit the volatilization of cyanide and is environmentally friendly and safe.

[0006] The application provides a preparation method of gold-plated nickel powder, comprising the following steps:

[0007] S1, mixing a weak alkali solution, a strong alkali solution and a surfactant to form a first mixed solution, and adding nickel powder to the first mixed solution to form a first mixture; the first mixture is subjected to temperature rising ultrasonic stirring, and the first mixture after temperature rising ultrasonic stirring is subjected to filtration separation to obtain a first nickel powder; the first nickel powder is washed;

[0008] S2, mixing the strong acid solution and the weak base solution to form a second mixed solution, and adding the cleaned first nickel powder into the second mixed solution to form a second mixture; performing warm ultrasonic stirring on the second mixture, and performing filtration separation on the second mixture after the warm ultrasonic stirring to obtain a second nickel powder; and cleaning the second nickel powder;

[0009] S3, mixing the strong acid solution, the weak base solution and a surfactant to form a third mixed solution, and dividing the third mixed solution into two parts; adding the cleaned second nickel powder into one part of the third mixed solution to form a third mixture; performing warm ultrasonic stirring on the third mixture, and performing filtration separation on the third mixture after the warm ultrasonic stirring to obtain a third nickel powder; mixing the third nickel powder and the other part of the third mixed solution to form a fourth mixture, performing warm ultrasonic stirring on the fourth mixture, and performing filtration separation on the fourth mixture after the warm ultrasonic stirring to obtain a fourth nickel powder; and cleaning the fourth nickel powder;

[0010] S4, providing a fourth mixed solution formed by mixing a gold salt, a weak acid solution and an anti-volatilization additive or formed by mixing a cyanide-free gold salt and a weak acid solution, and adding the cleaned fourth nickel powder into the fourth mixed solution to form a fifth mixture; performing warm ultrasonic stirring on the fifth mixture, and performing filtration separation on the fifth mixture after the warm ultrasonic stirring to obtain a fifth nickel powder with a gold-containing surface; and cleaning and drying the fifth nickel powder with the gold-containing surface to obtain a gold-plated nickel powder.

[0011] Preferably, the weak base solution in the S1, the S2 and the S3 is a solution containing any one or more of hydrogen peroxide, sodium carbonate, anhydrous sodium carbonate, aqueous sodium carbonate, sodium phosphate, potassium phosphate, ethylenediamine and triethanolamine; and the strong base solution in the S1 is a solution containing any one or more of potassium hydroxide, sodium hydroxide, calcium hydroxide and barium hydroxide.

[0012] Preferably, the strong acid solution in the S2 and the S3 is a solution containing any one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid and hydroiodic acid; and the weak acid solution in the S4 is a solution containing any one or more of cyanic acid, carbonic acid, hydrofluoric acid, acetic acid, hydrogen sulfide, hypochlorous acid, citric acid and potassium citrate.

[0013] Preferably, the surfactant in the S1 and the S3 is made of any one or more of sodium dodecyl sulfate, dodecyl phenol polyoxyethylene ether, cetyltrimethylammonium bromide, a detergent and a hand sanitizer.

[0014] Preferably, the nickel powder in S1 has a size of 1 nm-100 μm; and the nickel powder in S1 has any one of a spherical shape, a flaky shape and an irregular shape.

[0015] Preferably, the gold salt is potassium cyanide and / or potassium gold cyanide.

[0016] Preferably, the non-cyanide gold salt is sodium gold sulfite, and the preparation method of the sodium gold sulfite specifically comprises: S41, providing a gold chloride and sodium sulfite solution; S42, slowly pouring the gold chloride into the sodium sulfite solution while stirring to obtain the sodium gold sulfite.

[0017] Preferably, the temperature of the temperature-increasing ultrasonic stirring is 30-100 ℃, and the ultrasonic stirring time is 1-100 minutes.

[0018] Preferably, the anti-volatilization additive contains potassium phosphate and / or sodium phosphate.

[0019] Preferably, the solvent for cleaning the first nickel powder, the second nickel powder, the third nickel powder, the fourth nickel powder and the fifth nickel powder is deionized water and / or anhydrous ethanol; and the temperature for drying the fifth nickel powder is 25-100 ℃, and the drying time is 1-48 hours.

[0020] Compared with the related art, the present application provides a preparation method of gold-plated nickel powder, provides a fourth mixed solution formed by mixing a gold salt, a weak acid solution and an anti-volatilization additive or formed by mixing a non-cyanide gold salt and a weak acid solution, and adds a fourth nickel powder subjected to oil removal by an alkaline solution, acid washing and surface activation treatment into the fourth mixed solution to form a fifth mixed material; the fifth mixed material is subjected to temperature-increasing ultrasonic stirring, and the fifth mixed material after the temperature-increasing ultrasonic stirring is subjected to filtration separation to obtain the fifth nickel powder containing gold on the surface; the fifth nickel powder containing gold on the surface is cleaned and dried to obtain the gold-plated nickel powder. In the gold plating step of the nickel powder, the nickel powder is plated by adding an anti-volatilization additive or using a non-cyanide gold salt, which can effectively inhibit the volatilization of cyanide and is environmentally friendly and safe. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 FIG. 1 is a flowchart of a preparation method of gold-plated nickel powder according to the present application;

[0022] Fig. 2 FIG. 4 is a flowchart of a preparation method of sodium gold sulfite. DETAILED DESCRIPTION

[0023] The present application provides a preparation method of gold-plated nickel powder, which can effectively inhibit the volatilization of cyanide and is environmentally friendly and safe.

[0024] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0025] Please refer to the drawings of the embodiments of the present application Figs. 1-2 The present application provides a preparation method of gold-plated nickel powder, comprising the following steps:

[0026] S1, mixing a weak alkali solution, a strong alkali solution and a surfactant to form a first mixed solution, and adding nickel powder into the first mixed solution to form a first mixture; performing temperature-raising ultrasonic stirring on the first mixture, and performing suction filtration separation on the first mixture after temperature-raising ultrasonic stirring to obtain first nickel powder; and cleaning the first nickel powder.

[0027] S2, mixing a strong acid solution and a weak alkali solution to form a second mixed solution, and adding the cleaned first nickel powder into the second mixed solution to form a second mixture; performing temperature-raising ultrasonic stirring on the second mixture, and performing suction filtration separation on the second mixture after temperature-raising ultrasonic stirring to obtain second nickel powder; and cleaning the second nickel powder.

[0028] S3, mixing a strong acid solution, a weak alkali solution and a surfactant to form a third mixed solution, and dividing the third mixed solution into two parts; adding the cleaned second nickel powder into one part of the third mixed solution to form a third mixture; performing temperature-raising ultrasonic stirring on the third mixture, and after the third mixture after temperature-raising ultrasonic stirring is left to stand, transferring the solution of the third mixture to obtain third nickel powder; mixing the third nickel powder with the other part of the third mixed solution to form a fourth mixture, performing temperature-raising ultrasonic stirring on the fourth mixture, and performing filtration separation on the fourth mixture after temperature-raising ultrasonic stirring to obtain fourth nickel powder; and cleaning the fourth nickel powder.

[0029] S4, providing a fourth mixed solution formed by mixing a gold salt, a weak acid solution and a volatile prevention additive or formed by mixing a cyanide-free gold salt and a weak acid solution, and adding the cleaned fourth nickel powder into the fourth mixed solution to form a fifth mixture; performing temperature-raising ultrasonic stirring on the fifth mixture, and performing filtration separation on the fifth mixture after temperature-raising ultrasonic stirring to obtain the fifth nickel powder with gold on the surface; cleaning and drying the fifth nickel powder with gold on the surface to obtain gold-plated nickel powder.

[0030] Specifically, the weak base solution in the S1, the S2 and the S3 is a solution containing any one or more of hydrogen peroxide, sodium carbonate, anhydrous sodium carbonate, sodium carbonate with water, sodium phosphate, potassium phosphate, ethylenediamine and triethanolamine; the strong base solution in the S1 is a solution containing any one or more of potassium hydroxide, sodium hydroxide, calcium hydroxide and barium hydroxide. The strong acid solution in the S2 and the S3 is a solution containing any one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid and hydroiodic acid; the weak acid solution in the S4 is a solution containing any one or more of cyanic acid, carbonic acid, hydrofluoric acid, acetic acid, hydrogen sulfide acid, hypochlorous acid, citric acid and potassium citrate.

[0031] In the present embodiment, the surfactant in the S1 and the S3 is made of any one or more of sodium dodecyl sulfate, dodecyl phenol polyoxyethylene ether, cetyl trimethyl ammonium bromide, detergent and hand sanitizer.

[0032] Further, in the present embodiment, the size of the nickel powder in the S1 is 1 nm-100 μm; and the shape of the nickel powder in the S1 is any one of spherical, flaky and irregular; the gold salt is potassium cyanide gold and / or potassium subaurite.

[0033] It is worth mentioning that the cyanide-free gold salt is sodium sulfite, and the preparation method of the sodium sulfite specifically comprises: S41, providing a gold chloride and sodium sulfite solution; S42, slowly pouring the gold chloride into the sodium sulfite solution while stirring to obtain the sodium sulfite.

[0034] In the present embodiment, the temperature of the temperature rising ultrasonic stirring is 30℃-100℃, and the ultrasonic stirring time is 1 minute-100 minutes; the solvent for cleaning the first nickel powder, the second nickel powder, the third nickel powder, the fourth nickel powder and the fifth nickel powder is deionized water and / or anhydrous ethanol; and the fifth nickel powder is dried by placing the fifth nickel powder in a vacuum drying oven, and the drying temperature is set to 25℃-100℃, and the drying time is 1h-48h.

[0035] Compared with the related art, the present application provides a preparation method of gold-plated nickel powder, provides a fourth mixed solution formed by mixing a gold salt, a weak acid solution and a volatile-preventing additive or formed by mixing a cyanide-free gold salt and a weak acid solution, and adds the fourth nickel powder after oil removal, pickling and surface activation treatment in an alkaline solution into the fourth mixed solution to form a fifth mixed solution; the fifth mixed solution is subjected to warming and ultrasonic stirring, and the fifth mixed solution after warming and ultrasonic stirring is subjected to filtration separation to obtain the fifth nickel powder containing gold on the surface; the fifth nickel powder containing gold on the surface is subjected to cleaning and drying to obtain the gold-plated nickel powder. In the gold plating step of the nickel powder, the nickel powder is plated with gold by adding a volatile-preventing additive or using a cyanide-free gold salt, so that the volatilization of cyanide can be effectively inhibited, and the environment is safe.

[0036] It should be noted that the above-mentioned embodiments are understood as illustrative rather than limiting the protection scope of the present application, and the protection scope of the present application is subject to the claims. For those skilled in the art, some non-essential improvements and adjustments of the present application without departing from the essence and scope of the present application still belong to the protection scope of the present application.

Claims

1. A method for preparing gold-plated nickel powder, characterized in that: The method comprises the following steps: S1, mixing a weak base solution, a strong base solution, and a surfactant to form a first mixed solution, and adding nickel powder to the first mixed solution to form a first mixed material; heating and ultrasonically stirring the first mixed material, and filtering and separating the first mixed material after heating and ultrasonically stirring to obtain a first nickel powder; washing the first nickel powder; S2, mixing a strong acid solution and a weak base solution to form a second mixed solution, and adding the cleaned first nickel powder to the second mixed solution to form a second mixed material; The second mixed material is subjected to ultrasonic stirring at elevated temperature, and the second mixed material after the ultrasonic stirring is subjected to suction filtration to separate to obtain a second nickel powder; and the second nickel powder is washed; S3, mixing a strong acid solution, a weak base solution and a surfactant to form a third mixed solution, and dividing the third mixed solution into two parts; adding the cleaned second nickel powder to one part of the third mixed solution to form a third mixed material; performing ultrasonic stirring on the third mixed material at elevated temperature, and then allowing the third mixed material after the ultrasonic stirring to stand to transfer the solution of the third mixed material to obtain a third nickel powder; mixing the third nickel powder with another part of the third mixed solution to form a fourth mixed material, performing ultrasonic stirring on the fourth mixed material at elevated temperature, and filtering and separating the fourth mixed material after the ultrasonic stirring to obtain a fourth nickel powder; and cleaning the fourth nickel powder; S4, providing a fourth mixed solution formed by mixing a gold salt, a weak acid solution and an anti-volatile additive or by mixing a cyanide-free gold salt and a weak acid solution, and adding the cleaned fourth nickel powder to the fourth mixed solution to form a fifth mixed material; heating and ultrasonically stirring the fifth mixed material, and filtering and separating the fifth mixed material after heating and ultrasonically stirring to obtain a fifth nickel powder containing gold on the surface; washing and drying the fifth nickel powder containing gold on the surface to obtain a gold-plated nickel powder; the gold salt is potassium gold cyanide and / or potassium gold cyanide; the anti-volatile additive contains potassium phosphate and / or sodium phosphate.

2. The method for preparing gold-plated nickel powder according to claim 1, wherein The weak alkaline solution in S1, S2 and S3 is a solution containing any one or more of hydrogen peroxide, sodium carbonate, sodium phosphate, potassium phosphate, ethylenediamine and triethanolamine; the strong alkaline solution in S1 is a solution containing any one or more of potassium hydroxide, sodium hydroxide, calcium hydroxide and barium hydroxide.

3. The method for preparing gold-plated nickel powder according to claim 1, wherein The strong acid solution in S2 and S3 is a solution containing any one or more of hydrochloric acid, sulfuric acid, nitric acid, perchloric acid, hydrobromic acid, and hydroiodic acid; the weak acid solution in S4 is a solution containing any one or more of cyanic acid, carbonic acid, hydrofluoric acid, acetic acid, hydrosulfuric acid, hypochlorous acid, citric acid, and potassium citrate.

4. The method for preparing gold-plated nickel powder according to claim 1, wherein The surfactant in S1 and S3 is made of any one or more of sodium lauryl sulfate, dodecylphenol polyoxyethylene ether, and cetyltrimethylammonium bromide.

5. The method for preparing gold-plated nickel powder according to claim 1, wherein The nickel powder in S1 has a size of 1 nm to 100 μm; and the nickel powder in S1 has a shape of any one of spherical, flake, and irregular shapes.

6. The method for preparing gold-plated nickel powder according to claim 1, wherein The cyanide-free gold salt is sodium gold sulfite, and the preparation method of the sodium gold sulfite specifically includes: S41, providing gold chloride and sodium sulfite solution; S42, slowly pouring the gold chloride into the sodium sulfite solution while stirring to obtain the sodium gold sulfite.

7. The method for preparing gold-plated nickel powder according to claim 1, wherein The heating temperature of the ultrasonic stirring is 30° C. to 100° C., and the ultrasonic stirring time is 1 minute to 100 minutes.

8. The method for preparing gold-plated nickel powder according to claim 5, wherein The solvent for cleaning the first nickel powder, the second nickel powder, the third nickel powder, the fourth nickel powder and the fifth nickel powder is deionized water and / or anhydrous ethanol; and the temperature for drying the fifth nickel powder is 25° C. to 100° C., and the drying time is 1 hour to 48 hours.

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