Preparation method of high-purity gold for electron industry

An electronic industry, pure gold technology, applied in the field of high-purity precious metal preparation, can solve the problems of carry-in, poor surface cleanliness, affecting chip performance, etc., and achieve the effect of good smelting cleanliness

Inactive Publication Date: 2019-05-21
SINO PLATINUM METALS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In summary, it can be seen that although the purity of high-purity gold prepared by some existing methods can reach 99.999% (both in terms of metal elements), the use of graphite cathode plate materials, reducing agents, etc. in the preparation process inevitably leads to high-purity gold. C, S and other impurity elements
Using this kind of high-purity gold as raw material, the surface cleanliness is poor when it is smelted and processed into gold evaporation materials, and fine black particles appear when it is evaporated to the surface of the chip, which seriously affects the performance of the chip

Method used

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  • Preparation method of high-purity gold for electron industry
  • Preparation method of high-purity gold for electron industry
  • Preparation method of high-purity gold for electron industry

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Embodiment 1, see attached figure 1 , after rolling gold ingots (Au 99.95%), using aqua regia to dissolve and nitrate to obtain a chloroauric acid solution; adding sulfuric acid to maintain a concentration of 0.001mol / L, then using sodium hydroxide to adjust the pH=1 of the solution, and standing After 24 hours, the solution was filtered under reduced pressure with a 0.1 μm filter membrane to obtain a pure gold solution; slowly add superior pure hydrazine hydrochloride to this solution, stir, and fully reduce until the solution is nearly colorless, filter, and fully wash with deionized water , to obtain gold powder; put the gold powder in a polytetrafluoroethylene container, use 30% nitric acid + 20% hydrofluoric acid mixed solution, stir and boil for 60 minutes, filter, fully wash with 80°C deionized water until neutral, and vacuum dry Finally, high-purity gold is obtained.

Embodiment 2

[0018] Embodiment 2, see attached figure 1 , after rolling gold ingots (Au 99.95%), using aqua regia to dissolve and nitrate to obtain a chloroauric acid solution; add sulfuric acid to maintain a concentration of 0.001mol / L, then use sodium hydroxide to adjust the pH of the solution to 3, and let it stand After 24 hours, the solution was filtered under reduced pressure using a 0.2 μm filter membrane to obtain a pure gold solution; slowly add superior pure hydrazine hydrochloride to this solution, stir, and fully reduce until the solution is nearly colorless, filter, and fully wash with deionized water , to obtain gold powder; put the gold powder in a polytetrafluoroethylene container, use 30% nitric acid + 20% hydrofluoric acid mixed solution, stir and boil for 60 minutes, filter, fully wash with 80°C deionized water until neutral, and vacuum dry Finally, high-purity gold is obtained.

Embodiment 3

[0019] Embodiment 3, see attached figure 1 , after gold ingot (Au 99.95%) is rolled into slices, use aqua regia to dissolve, catch up with nitrate, obtain chloroauric acid solution; add sulfuric acid to keep concentration 0.001mol / L, then adopt sodium hydroxide to adjust solution pH=2, leave standstill After 24 hours, the solution was filtered under reduced pressure using a 0.1 μm filter membrane to obtain a pure gold solution; slowly add superior pure hydrazine hydrochloride to this solution, stir, and fully reduce until the solution is nearly colorless, filter, and deionize with 80°C Fully wash with water to obtain gold powder; place the gold powder in a polytetrafluoroethylene container, use a mixed solution of 30% nitric acid + 20% hydrofluoric acid, stir and boil for 60 minutes, filter, and fully wash with 80°C deionized water until neutral , after vacuum drying, high-purity gold was obtained.

[0020] The typical high-purity gold prepared by the present invention adopts...

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Abstract

The invention discloses a preparation method of high-purity gold for the electron industry. After gold ingots are rolled into pieces, the pieces are dissolved in aqua regia, a solution is made, nitrate is removed, and a chloroauric acid solution is obtained; sulfuric acid and sodium hydroxide are added to the gold solution, the pH value of the solution is adjusted, the solution is fully stirred and left to stand, and impurities, namely, metal ions, are deposited fully; the solution is subjected to filtration under reduced pressure by the aid of a micro-pore filtering film after being left to stand, and a pure gold solution is obtained; a reducing agent is slowly added to the pure gold solution, the solution is stirred, full reduction, filtration and washing are performed, and gold powder is obtained; the gold powder is placed in a polytetrafluoroethylene container to be boiled and washed with a dilute nitric acid and hydrofluoric acid mixed solution, the solution is filtered and is washed with hot deionized water to be neutral, vacuum drying is performed, and the high-purity gold is obtained. The gold prepared with the method has the purity higher than 99.999%, has the C and S content lower than 1 ppm, has the good smelting cleanliness and can be used as a raw material for high-purity gold evaporation materials for the electron industry.

Description

technical field [0001] The invention relates to a preparation method of high-purity precious metals, in particular to a preparation method of high-purity gold used in the electronics industry. Background technique [0002] High-purity gold has the characteristics of low and stable contact resistance, good electrical and thermal conductivity, easy bonding, easy film formation, and good adhesion to semiconductor substrates. It is an important evaporation coating material in the electronics industry such as integrated circuit devices and semiconductor devices. With the development of large-scale integrated circuits in the direction of high speed, small size, and narrow spacing, higher requirements are put forward for the quality of gold evaporation materials, Au>99.999%, good melting cleanliness (no black matter on the surface of gold liquid after melting, After being processed into gold evaporation material, there are no black particles on the surface of the chip after evap...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B11/00C22B3/22C22B3/44
CPCY02P10/20
Inventor 董海刚裴洪营赵家春崔浩杨海琼吴跃东童伟锋保思敏王亚雄吴晓峰
Owner SINO PLATINUM METALS CO LTD
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