Various high purity gases have been widely used in the production of electronic devices. According to the different USES of high purity gas in the process, it can be divided into maintenance gas, reaction gas and carrier gas.

Maintenance gases are hydrogen, nitrogen, oxygen and their mixtures. In order to obtain hydrogen and ammonia gas, in order to obtain higher purity hydrogen, generally choose electrolysis pure water method. This method requires a large amount of electricity to electrolyze water, usually up to 4.5-5.5kwh /Nm3H2, resulting in a high cost.

In order to reduce the consumption of electricity, reduce the cost, are developing and using all kinds of mixture. In the meantime, nitrogen - hydrogen mixture was used most. In foreign countries, liquid hydrogen and liquid nitrogen vaporization are used to obtain nitrogen-hydrogen mixture, and liquid nitrogen decomposition method is also used to obtain nitrogen-hydrogen mixture.

The method of obtaining nitrogen-oxygen mixture by the vaporization of liquid hydrogen and liquid nitrogen is higher in investment and cost because the process of liquefaction and vaporization is adopted. Abroad, because the degree of specialization of production is high, use a unit to choose this kind of method to obtain mixture more. If obtain liquid hydrogen and liquid nitrogen from the by-product of professional aluminum alloy door and window factory or large joint enterprise at home, its cost is higher than the hydrogen and chlorine gas obtained by electrolysis hydrogen and "air separation" nitrogen several times. The mixture of nitrogen and oxygen obtained by the decomposition of liquid ammonia, because of the different sources of liquid nitrogen, most of the poor quality, which still contains undecomposed ammonia, water and oxygen impurities. In addition, more liquid nitrogen from fertilizer plants, now, the supply is more serious, so the cost is higher.

Nitrogen-hydrogen mixture can not only replace oxygen as maintenance gas in the production of electronic devices, but also be widely used in metallurgy, chemical, mechanical and other industries. Once widely used, it will produce considerable economic and social benefits.