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Ultrapure water for the electronics industry Semiconductors, integrated circuit chips and packages, liquid crystal displays, high-precision circuit boards, optoelectronic devices, various electronic devices, microelectronics industry, large-scale and ultra-large-scale integrated circuits require a large amount of high-purity water and ultra-pure water to clean semi-finished products and finished products. The higher the integration level of integrated circuits, the higher the requirements for water quality. At present, my country's Ministry of Electronics Industry divides electronic-grade water quality technology into five industry standards, namely 18MΩ.cm, 15MΩ.cm, 10MΩ.cm, 2MΩ.cm, and 0.5MΩ.cm, to distinguish different water qualities. The process of preparing super water in the electronics industry is roughly divided into the following types:: 1. The traditional water treatment method using ion exchange resin to prepare ultrapure water. The basic process flow is as follows: Raw water → Sand carbon filter → Precision filter → Raw water tank → Yang bed → Yin bed → Mixed bed (multiple bed) → Pure water tank → Pure water pump → Post precision filter → Water point 2. The combination of reverse osmosis water treatment equipment and ion exchange equipment is used. The basic process flow is as follows: Raw water → Sand carbon filter → Precision filter → Raw water tank → Reverse osmosis equipment → Mixed bed (multiple bed) → Pure water tank → Pure water pump → Post-precision filter → Water point 3. Use reverse osmosis water treatment equipment and electrodeionization (EDI) equipment to match. This is the latest process for producing ultrapure water. It is also an ultrapure water preparation process that is environmentally friendly, economical and has great development potential. Its basic process flow is:: Raw water → Sand carbon filter → Precision filter → Raw water tank → Reverse osmosis equipment → Electrodeionization (EDI) → Pure water tank → Pure water pump → Post-precision filter → Water point Comparison of three processes for preparing ultrapure water for the electronics industry. The current processes for preparing ultrapure water for the electronics industry are basically the above three. Most of the remaining processes are derived from different combinations of the above three basic processes. Their advantages and disadvantages are now listed below.: 1. The first type uses ion exchange resin. Its advantages are low initial investment and small space occupation. However, the disadvantage is that it requires frequent ion regeneration, consumes a lot of acid and alkali, and causes certain damage to the environment. 2. The second method uses reverse osmosis as pretreatment and is equipped with ion exchange equipment. Its characteristic is that the initial injection time is higher than that of ion exchange resin, but the regeneration cycle of the ion equipment is relatively long, and the acid and alkali consumption is much less than that of simply using ion resin. But it is still somewhat destructive to the environment. 3. The third method uses reverse osmosis for pretreatment and is equipped with an electrodeionization (EDI) device. This is currently the most economical and environmentally friendly process for producing ultrapure water. It can continuously produce ultrapure water without using acid and alkali for regeneration, and is not destructive to the environment. The disadvantage is that the initial investment is too expensive compared to the above two methods. This post was last edited by johncom on 2009-3-6 10:05 ]