In the manufacturing processes of the electronics, semiconductor, liquid crystal display and photovoltaic industries, extremely pure ultrapure water is often required. If the quality of pure water fails to meet the requirements of production process water or is unstable, it will affect the treatment effect and service life of subsequent processes.
Typical process flow of ultra-pure water equipment in the electronics industry
1. The ion exchange method is adopted, and its process is as follows: tap water → electric valve → multi-media filter → activated carbon filter → water softener → intermediate water tank → low-pressure pump → precision filter → cation resin bed → anion resin bed → mixed cation and anion resin bed → microporous filter → water usage point n2. The two-stage reverse osmosis method is adopted, and its process is as follows: Tap water → Electric valve → multi-media filter → Activated carbon filter → water softener → Intermediate water tank → Low-pressure pump → Precision filter → first-stage reverse osmosis main unit →PH adjustment → mixer → second-stage reverse osmosis main unit (reverse osmosis membrane surface carries positive charge) → Pure water tank → Pure water pump → Micro-pore filter → Ultra-pure water equipment at water usage point
3. It adopts a high-efficiency reverse osmosis combined with EDI method. The process is as follows (the latest technology offers the best cost performance) : Comparison of three processes: tap water → electric valve → multi-media filter → activated carbon filter → water softener → intermediate water tank → low-pressure pump →PH adjustment system → high-efficiency mixer → precision filter → high-efficiency reverse osmosis → intermediate water tank →EDI water pump →EDI system → micro-pore filter → water usage point
The processes for preparing ultrapure water for the electronics industry are basically the above three. The rest of the process flows are mostly derived from different combinations and pairings on the basis of the above three basic process flows. Their advantages and disadvantages are listed respectively as follows:
The first type uses traditional ion exchange resins. Its advantages lie in the low initial investment and small space occupation, but the disadvantages are that it requires frequent ion regeneration, consumes a large amount of acid and alkali, and causes certain damage to the environment.
The second type employs reverse osmosis + ion exchange equipment. Its characteristic is that the initial investment is slightly higher than that of the method using ion exchange resin, but the ion regeneration cycle is relatively longer, and the consumption of acid and alkali is much less than that of the method using ion resin alone. It is a relatively economical and popular craft.
The third method uses reverse osmosis as pretreatment and is equipped with an electro-deionization device. This is currently the most advanced and environmentally friendly process for producing ultrapure water. It can continuously produce ultrapure water without the need for acid and alkali regeneration, causing little damage to the environment. Its drawback lies in that the initial investment is relatively too expensive compared to the above two methods.
The EDI ultra-pure water equipment provided by Leberui produces water that meets the standard water quality. It usually uses the source water at the national standard water level for tap water. In terms of the selection of materials for the water treatment equipment process, it refers to the customer's requirements and has a higher cost performance and reliability.
