阅读说明：本技术 一种电子级氢氟酸的生产工艺方法 (Production process method of electronic-grade hydrofluoric acid ) 是由 杨英春 曹玉宽 于 2020-07-07 设计创作，主要内容包括：本发明涉及化工生产领域的一种电子级氢氟酸的生产工艺方法,其生产工艺方法包括以下步骤：a、预处理；b、精馏；c、吸收；d、调节；e、精密过滤；f、灌装,本发明在无水氢氟酸进入再精馏工艺前设置预处理工艺,通过该预处理工艺中强氧化剂的强氧化性,使得氢氟酸内含有的部分杂质得以氧化为更高价态的物质,从而通过改变其价态来改变其物理性质,确保了后续再精馏过程中能够得以除去,再通过精密过滤器对中间产品进行过滤,使得成品中含有的微小颗粒杂质能够得以更一步清除,设置过滤器的目的是确保对生产过程中的一些外部影响因素的消除,使得产品质量标均能满足UPS级质量标准要求,UPS级产品达成率达到85％以上,产品的质量提高有很大保证。(The invention relates to a production process method of electronic grade hydrofluoric acid in the field of chemical production, which comprises the following steps: a. pre-treating; b. rectifying; c. absorption; d. adjusting; e. performing precision filtration; f. the method is characterized in that a pretreatment process is arranged before anhydrous hydrofluoric acid enters a re-rectification process, partial impurities contained in the hydrofluoric acid are oxidized into substances with higher valence states through the strong oxidizing property of a strong oxidizing agent in the pretreatment process, so that the physical properties of the hydrofluoric acid are changed by changing the valence states of the hydrofluoric acid, the removal of the hydrofluoric acid in the subsequent re-rectification process is ensured, and an intermediate product is filtered through a precision filter, so that fine particle impurities contained in a finished product can be further removed, the filter is arranged for eliminating external influence factors in the production process, the quality standard of the product can meet the standard requirement of UPS-grade quality, the achievement rate of the UPS-grade product reaches more than 85%, and the quality improvement of the product is greatly ensured.)

1. The production process method of the electronic grade hydrofluoric acid is characterized by comprising the following steps of:

a. pretreatment: pumping industrial anhydrous hydrogen fluoride into a degassing tower in a continuous mode, removing trace low-boiling-point substances, adding a strong oxidant, and oxidizing impurities in the industrial anhydrous hydrogen fluoride by using the strong oxidant for 3.3-4.2 hours;

b. and (3) rectification: adding the pretreated industrial anhydrous hydrogen fluoride into a distillation tower for fine distillation to obtain high-purity hydrogen fluoride gas, and discharging tower bottom liquid to prepare industrial hydrofluoric acid;

c. absorption: introducing high-purity hydrogen fluoride gas into an absorption tower, and condensing the high-purity hydrogen fluoride gas by pure water in the absorption tower, wherein the input weight ratio of the high-purity hydrogen fluoride to the pure water is 1.03-1.15:1, so as to obtain aqueous hydrofluoric acid liquid;

d. adjusting: the adjusting tower adjusts the concentration of the hydrofluoric acid liquid with pure water to obtain an intermediate product;

e. and (3) precise filtration: placing the intermediate product in a precision filter for precision filtration, and filtering fine particle impurities;

f. filling: and d, carrying out dust-free canning on the liquid filtered in the step d to obtain the electronic grade hydrofluoric acid product.

2. The process for producing electronic grade hydrofluoric acid according to claim 1, wherein: the strong oxidant in the step a is potassium permanganate or hydrogen peroxide or the combination of the potassium permanganate and the hydrogen peroxide, and the dosage of the strong oxidant is 0.028-0.033% of the mass of the industrial anhydrous hydrogen fluoride liquid.

3. The process for producing electronic grade hydrofluoric acid according to claim 1, wherein: the temperature of the tower kettle position in the step b is controlled to be 20-22 ℃, and the temperature of the outlet position of the overhead condenser is controlled to be 14-16 ℃.

4. The process for producing electronic grade hydrofluoric acid according to claim 1, wherein: the concentration of the hydrofluoric acid water liquid in the step c is 45-70%.

5. The process for producing electronic grade hydrofluoric acid according to claim 1, wherein: the concentration of the intermediate product in the step d is 48.5-49.5%.

6. The process for producing electronic grade hydrofluoric acid according to claim 1, wherein: the specification of the precision filter is 0.05-0.2 μm.

Technical Field

The invention relates to the field of chemical production, in particular to a production process method of electronic-grade hydrofluoric acid.

Background

With the development of high-end semiconductors in China, particularly the development of chip technology in China, the demand of electronic-grade hydrofluoric acid for cleaning and etching Integrated Circuit (IC) and very large scale integrated circuit (VLSI) chips is high all the time, and the quality requirement is higher and higher along with the development of the industry. The development of electronic grade hydrofluoric acid, which is one of key basic chemical materials in the manufacturing process of the microelectronic industry, in China, namely, the matters in recent years, is mainly limited by the limitation that the technology is monopolized abroad, the quality of the electronic grade hydrofluoric acid in China is always in the middle and low end markets, and the high-end high-quality electronic grade hydrofluoric acid is always controlled by foreign enterprises.

For electronic grade hydrofluoric acid, the main technical difficulty is in the aspect of purifying the main component, namely hydrofluoric acid, namely: how to remove impurities contained in hydrofluoric acid. At present, several manufacturers in China are all's ' repugnance ' in the eight immortals, and no clear technical scheme exists, so that on one hand, the technical protection is realized, and the technology is not disclosed for the benefit of people; on the other hand, it is true that this level, and there is little technology in place.

The basic process technology of the electronic-grade hydrofluoric acid is to purify anhydrous hydrofluoric acid again by rectification and then dilute the purer hydrofluoric acid and pure water to obtain 49 +/-0.5% electronic-grade hydrofluoric acid product. The prior production technology is basically a paper on the purification of hydrofluoric acid in the actual production process, and all people adopt the finished hydrofluoric acid in an irreconcilable way, further purify impurities contained in the hydrofluoric acid by a re-rectifying device, and then prepare the finished electronic grade hydrofluoric acid by using the purified hydrofluoric acid and pure water as a diluent. The electronic grade hydrofluoric acid prepared by the general method is basically at the middle and low end levels (EL grade and UP grade) and can not reach the middle and high end market quality standards (UPS grade and UPSS grade).

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a production process method of electronic-grade hydrofluoric acid, so that a purer electronic-grade hydrofluoric acid product which better meets the quality standard requirement can be prepared, the product quality can be better ensured, and the grade of the product is better improved.

In order to achieve the purpose, the invention is realized by the following technical scheme:

a production process method of electronic grade hydrofluoric acid comprises the following steps:

a. pretreatment: pumping industrial anhydrous hydrogen fluoride into a degassing tower in a continuous mode, removing trace low-boiling-point substances, adding a strong oxidant, and oxidizing impurities in the industrial anhydrous hydrogen fluoride by the strong oxidant for 3.3-4.2 hours;

b. and (3) rectification: adding the pretreated industrial anhydrous hydrogen fluoride into a distillation tower for fine distillation to obtain high-purity hydrogen fluoride gas, and discharging tower bottom liquid to prepare industrial hydrofluoric acid;

c. absorption: introducing high-purity hydrogen fluoride gas into an absorption tower, and condensing the high-purity hydrogen fluoride gas by pure water in the absorption tower, wherein the input weight ratio of the high-purity hydrogen fluoride to the pure water is 1.03-1.15:1, so as to obtain aqueous hydrofluoric acid liquid;

d. adjusting: the adjusting tower adjusts the concentration of the hydrofluoric acid liquid with pure water to obtain an intermediate product;

e. and (3) precise filtration: placing the intermediate product in a precision filter for precision filtration, and filtering fine particle impurities;

f. filling: and d, carrying out dust-free canning on the liquid filtered in the step d to obtain an electronic grade hydrofluoric acid product.

Preferably, the strong oxidant in the step a is potassium permanganate or hydrogen peroxide or a combination of the potassium permanganate and the hydrogen peroxide, and the dosage of the strong oxidant is 0.028-0.033% of the mass of the industrial anhydrous hydrogen fluoride liquid.

Preferably, the temperature of the bottom position of the tower in the step b is controlled to be 20-22 ℃, and the temperature of the outlet position of the overhead condenser is controlled to be 14-16 ℃.

Preferably, the concentration of the aqueous hydrofluoric acid liquid in the step c is 45-70%.

Preferably, the concentration of the intermediate product in the step d is 48.5-49.5%.

Preferably, the size of the precision filter is 0.05-0.2 μm.

Has the advantages that:

the invention sets a pretreatment process before anhydrous hydrofluoric acid enters a re-rectification process, partial impurities contained in the hydrofluoric acid are oxidized into substances with higher valence state through the strong oxidizing property of a strong oxidizing agent in the pretreatment process, so that the physical properties of the hydrofluoric acid are changed by changing the valence state of the hydrofluoric acid, the removal of the hydrofluoric acid in the subsequent re-rectification process is ensured, and an intermediate product is filtered through a precision filter, so that micro particle impurities contained in a finished product can be further removed, the filter is set to ensure the elimination of some external influence factors in the production process, and the filter is matched with other processes, so that the product quality standard can meet the UPS quality standard requirement, the achievement rate of the UPS product reaches more than 85 percent, and the quality improvement of the product is greatly ensured.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in the following with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.