Ultrapure Water Cleaning
This page provides an explanation of ultrapure water cleaning at TDC
Please also refer to the following pages for information on TDC’s cleaning technologies and equipment.
What is Pure Water/Ultrapure Water?
In general, pure water is water from which impurities have been removed by distillation, ion exchange, or other purification techniques. Highly purified water that is as close to H2O as possible by removing residual particulates, organic matter, viable organisms, dissolved gases, etc. is called “ultrapure water. Although there is no clear standard for pure water and ultrapure water, water with an electrical resistivity of approximately 0.1 to 15 MΩ-cm is generally defined as pure water, and water with an electrical resistivity as close as possible to 18.24 MΩ-cm, the theoretical resistivity of pure water, is generally defined as ultrapure water.
What is the difference between pure water and ultrapure water?
As mentioned above, “pure water” is water from which impurities have been removed, and “ultrapure water” is water from which further impurities have been removed and which is extremely pure and close to H2O. Purity is expressed by electrical resistivity, and “high electrical resistivity” is essential for cleaning precision equipment and parts. Therefore, ultrapure water is an indispensable cleaning method in the field of precision processing.
Types of Pure Water and Ultrapure Water
Pure water and ultrapure water can be classified into the following categories according to the method used to remove impurities.
- Demineralized water
Water from which salts have been removed by ion exchange resins, etc. - RO water
Water that has been passed through a reverse osmosis membrane - Distilled water
Water that has been cooled to a liquid from water vapor
Properties of Pure Water and Ultrapure Water
Pure water and ultrapure water, also known as “hungry water,” have the property of easily taking in and dissolving other substances. Tap water, which is familiar to us, also has the property of dissolving substances, and this property becomes stronger the more impurity-free it is. By cleaning with pure water and ultrapure water, even invisible ions and organic matter can be removed to the maximum extent possible, which is why they are used in the manufacturing and processing processes of semiconductors and other precision equipment.
Applications of Pure Water/Ultrapure Water
Compared to general tap water and industrial water, pure water and ultrapure water are used in cleaning processes that require a nano-level of precision.
| Type of water | Usage | Electrical resistivity |
| Ultrapure water |
|
15MΩ-cm or higher |
| Pure water |
|
0.1～15MΩ・cm |
| Tap water |
|
0.002～0.02MΩ・cm |
| Industrial water |
|
|
| River water, lake water, groundwater |
|
Ultrapure Water Cleaning at TDC
TDC has installed the following ultrapure water production equipment.
| Brand | Equipment |
| ORGANO | UC–2600 ultrapure water production equipment |
| ELGA | ultrapure water generator (tank capacity 60L) Purelab Chorus |
By using “ultrapure water equipment,” which can perform cleaning that is impossible with pure water equipment, we are able to perform the cleaning required for more precision equipment. The following is the ultrapure water generation process of the ultrapure water generator (Organo UC-2600).
Please consult with TDC about cleaning using ultrapure water.
TDC’s dedicated cleaning system using ultrapure water makes it possible to reduce particle adhesion to the utmost limit. We can provide precision cleaning of semiconductor wafers from a single wafer, so please feel free to contact us. Please feel free to contact us for requests and inquiries.
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