Preparation method of gold-plated nickel powder

Abstract

The invention relates to a preparation method of gold-plated nickel powder, which comprises the following steps: providing a fourth mixed solution formed by mixing gold salt, a weak acid solution and an anti-volatilization additive or formed by mixing cyanide-free gold salt and a weak acid solution, fourth nickel powder subjected to alkaline solution oil removal, acid pickling and surface activation treatment is added into the fourth mixed solution to form a fifth mixed material; the fifth mixed material is subjected to heating ultrasonic stirring, the fifth mixed material subjected to heating ultrasonic stirring is filtered and separated, and fifth nickel powder with the surface containing gold is obtained; and the fifth nickel powder with the surface containing gold is cleaned and dried, and the gold-plated nickel powder is obtained. The anti-volatilization additive is added or cyanide-free gold salt is used for gold plating, volatilization of cyanide can be effectively inhibited, and the method is environmentally friendly and safe.

Description

Technical Field

[0001] The invention belongs to the technical field of microelectronic packaging, and in particular relates to a method for preparing gold-plated nickel powder. Background Art

[0002] Gold has very stable chemical properties and will not be directly oxidized by oxygen at low or high temperatures. It also has good electrical and thermal conductivity. Nickel powder has good oxidation resistance, high electrical conductivity, and low electrical mobility. It is widely used in catalysts, sintering activators, conductive slurries, conductive adhesives, metal filtration, batteries and other products.

[0003] Package test sockets have gained wide attention due to the simplicity they provide in device testing, eliminating the soldering of integrated circuits (ICs) on printed circuit boards (PCBs). Two common sockets used in electronic IC packaging are pogo-pin sockets and elastomer sockets. Compared with the pogo-pin type, the appeal of elastomer sockets lies mainly in the reduction of crosstalk between pins due to their lower height. The conductor of the elastic socket is based on gold-plated nickel powder, which is compressed into a columnar shape during operation to form a conductive path. In high-frequency signals, when there is alternating current or alternating electromagnetic field in the conductor, the current distribution inside the conductor is uneven, and the current is 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 will produce cyanide, and cyanide is easy to volatilize, which will pollute the environment and cause certain harm to human functions, and the environmental protection and safety are not high.

[0004] Therefore, the present invention provides a method for preparing gold-plated nickel powder to solve the above technical problems. Summary of the invention

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

[0006] The present invention provides a method for preparing gold-plated nickel powder, comprising the following steps:

[0007] S1, mixing a weak alkaline solution, a strong alkaline 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;

[0008] S2, mixing a strong acid solution and a weak base solution to form a second mixed solution, and adding the washed first nickel powder to the second mixed solution to form a second mixed material; heating and ultrasonically stirring the second mixed material, and filtering and separating the heated and ultrasonically stirred second mixed material to obtain a second nickel powder; washing the second nickel powder;

[0009] 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 transferring the solution of the third mixed material after the ultrasonic stirring at elevated temperature 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 at elevated temperature 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-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 the heating and ultrasonic 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.

[0011] Preferably, the weak alkaline solution in S1, S2 and S3 is a solution containing any one or more of hydrogen peroxide, sodium carbonate, anhydrous sodium carbonate, hydrous 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.

[0012] Preferably, 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.

[0013] Preferably, the surfactant in S1 and S3 is made of any one or more of sodium dodecyl sulfate, dodecylphenol polyoxyethylene ether, hexadecyltrimethylammonium bromide, detergent and hand soap.

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

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

[0016] Preferably, 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.

[0017] Preferably, the heating temperature of the ultrasonic stirring is 30° C. to 100° C., and the ultrasonic stirring time is 1 minute to 100 minutes.

[0018] Preferably, the anti-volatile 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°C to 100°C, and the drying time is 1h to 48h.

[0020] Compared with the related art, the present invention provides a method for preparing gold-plated nickel powder, 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 a fourth nickel powder after alkaline solution degreasing, pickling and surface activation treatment to the fourth mixed solution to form a fifth mixed material; the fifth mixed material is subjected to temperature-raising ultrasonic stirring, and the fifth mixed material after temperature-raising ultrasonic stirring is filtered and separated to obtain the fifth nickel powder containing gold on the surface; the fifth nickel powder containing gold on the surface is washed and dried to obtain the gold-plated nickel powder. In the step of gold-plating the nickel powder, the present invention can effectively inhibit the volatilization of cyanide by adding an anti-volatile additive or using a cyanide-free gold salt to gold-plate the nickel powder, which is environmentally friendly and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic flow chart of a method for preparing gold-plated nickel powder;

[0022] Figure 2 The figure is a schematic flow chart of the method for preparing sodium gold sulfite. DETAILED DESCRIPTION

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

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Please also refer to the attached Figure 1-2 The present invention provides a method for preparing gold-plated nickel powder, comprising the following steps:

[0026] S1, mixing a weak alkaline solution, a strong alkaline 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.

[0027] S2, mixing a strong acid solution and a weak base solution to form a second mixed solution, and adding the washed first nickel powder to the second mixed solution to form a second mixed material; heating and ultrasonically stirring the second mixed material, and filtering and separating the heated and ultrasonically stirred second mixed material to obtain a second nickel powder; washing the second nickel powder;

[0028] 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 transferring the solution of the third mixed material after the ultrasonic stirring at elevated temperature 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 at elevated temperature to obtain a 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 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 the heating and ultrasonic stirring to obtain the fifth nickel powder containing gold on the surface; washing and drying the fifth nickel powder containing gold on the surface to obtain gold-plated nickel powder.

[0030] Specifically, the weak alkaline solution in S1, S2 and S3 is a solution containing any one or more of hydrogen peroxide, sodium carbonate, anhydrous sodium carbonate, hydrous 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. 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.

[0031] In this embodiment, the surfactant in S1 and S3 is made of any one or more of sodium dodecyl sulfate, dodecylphenol polyoxyethylene ether, hexadecyltrimethylammonium bromide, detergent and hand soap.

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

[0033] It is worth mentioning that 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.

[0034] In this embodiment, the heating temperature of the ultrasonic stirring is 30°C to 100°C, and the ultrasonic stirring time is 1 minute to 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°C to 100°C, and the drying time is 1h to 48h.

[0035] Compared with the related art, the present invention provides a method for preparing gold-plated nickel powder, 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 a fourth nickel powder after alkaline solution degreasing, pickling and surface activation treatment to the fourth mixed solution to form a fifth mixed material; the fifth mixed material is subjected to temperature-raising ultrasonic stirring, and the fifth mixed material after temperature-raising ultrasonic stirring is filtered and separated to obtain the fifth nickel powder containing gold on the surface; the fifth nickel powder containing gold on the surface is washed and dried to obtain the gold-plated nickel powder. In the step of gold-plating the nickel powder, the present invention can effectively inhibit the volatilization of cyanide by adding an anti-volatile additive or using a cyanide-free gold salt to gold-plate the nickel powder, which is environmentally friendly and safe.

[0036] It should be noted that the above-described embodiments should be understood as illustrative rather than limiting the scope of protection of the present invention, and the scope of protection of the present invention shall be subject to the claims. For those skilled in the art, some non-essential improvements and adjustments made to the present invention still fall within the scope of protection of the present invention without departing from the essence and scope of the present invention.

Claims

1. A method for preparing gold-plated nickel powder, characterized in that: The method comprises the following steps: S1, mixing a weak alkaline solution, a strong alkaline 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 the strong acid solution and the 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; Performing ultrasonic stirring at elevated temperature on the second mixed material, and performing suction filtration and separation on the second mixed material after the ultrasonic stirring at elevated temperature to obtain a second nickel powder; and washing the second nickel powder; 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 transferring the solution of the third mixed material after the ultrasonic stirring at elevated temperature 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 at elevated temperature 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 the heating and ultrasonic stirring to obtain a fifth nickel powder containing gold on the surface; The fifth nickel powder containing gold on the surface is cleaned and dried to obtain gold-plated nickel powder.

2. The method for preparing a 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, anhydrous sodium carbonate, hydrous 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 a 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 a gold-plated nickel powder according to claim 1, wherein The surfactant in S1 and S3 is made of any one or more of sodium dodecyl sulfate, dodecylphenol polyoxyethylene ether, hexadecyltrimethylammonium bromide, detergent and hand soap.

5. The method for preparing a gold-plated nickel powder according to claim 1, wherein The nickel powder in S1 has a size of 1 nm-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 a gold-plated nickel powder according to claim 1, wherein The gold salt is potassium gold cyanide and / or potassium gold cyanide.

7. The method for preparing a 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.

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

9. The method for preparing a gold-plated nickel powder according to claim 5, wherein: The anti-volatilization additive contains potassium phosphate and / or sodium phosphate.

10. The method for preparing a gold-plated nickel powder according to claim 5, characterized in that: 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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