RELATIONSHIP BETWEEN WATER QUALITIES AND TREATMENTS IN THE ULTRA-PUREWATER PRODUCTION SYSTEM

In an ultra pure water (UPW) production system which can satisfy the w ater qualities for 4 megabit DRAM, the changes in water qualities from a tap water(58.4 mg/dm(3) as CaCO3, hardness) as a raw water to UPW w ere followed from the view of the micro-structure and microdynamic beh avior of water molecules with increasing of the water purity by a comp lex permittivity and O-17-NMR measurements, as well as measurements of resistivity, density, and so on. The dielectric relaxation time and s pin-lattice relaxation time of O-17 nuclei related to the microdynamic behavior of water molecules indicated a trace change between the tap water and UPW. However, the dielectric parameter alpha which character izes a symmetric distribution of relaxation times was gradually lowere d with increasing of the water purity, The relationship between the ha lf-width of O-17 magnetic resonance and pH gave the rate constants for the prototropic charge migration in water, The difference of alpha an d density between the tap water and UPW became a measure of water puri ty.