Customized double-pass RO plus EDI and polishing mixed bed solution for PCB production water

Ultrapure water is an important production utility in PCB manufacturing. It is widely used for circuit board cleaning, precision rinsing, chemical process support, and final washing steps. If dissolved salts, hardness, residual chlorine, particles, organics, or microorganisms remain in the water, they may affect surface cleanliness, reduce process stability, and increase product defect risk.

To support its production line water requirements, a PCB factory in Cambodia selected Zhongnuo Water Treatment to design and manufacture a 1 m3/h ultrapure water system. The solution converts municipal tap water into stable ultrapure process water through pretreatment, double-pass RO, EDI polishing, UV sterilization, storage, polishing mixed bed treatment, and terminal filtration.

The client needed a compact but complete ultrapure water system that could support PCB production with stable quality and practical operation.

◎  PCB production required stable high-purity water

Circuit board cleaning and rinsing processes are sensitive to ionic residues, fine particles, and organic contamination. Unstable water quality could affect product consistency and increase the risk of defects.

◎  Municipal feed water required deep treatment

Although municipal tap water was available, residual chlorine, hardness, suspended solids, and dissolved salts still needed to be reduced before ultrapure water could be supplied to production points.

◎  The system needed a compact layout for a 1 m3/h capacity

The factory required a small-capacity system that still included complete pretreatment, double-pass RO, EDI, and final polishing to meet electronic manufacturing water needs.

◎  Final water quality protection was critical

PCB production water must remain clean through storage and distribution. UV sterilization, polishing mixed bed treatment, and terminal filtration were included to strengthen final water quality assurance.

Municipal Tap Water  ->  Raw Water Tank  ->  Raw Water Pump  ->  Multi-media Filter  ->  Activated Carbon Filter  ->  Softening Water Filter  ->  Salt Tank  ->  Security Filter  ->  First-stage High Pressure Pump  ->  First-stage RO System  ->  Second-stage High Pressure Pump  ->  Second-stage RO System  ->  EDI Booster Pump  ->  EDI System  ->  UV Sterilization  ->  Ultrapure Water Tank  ->  Water Supply System  ->  Polishing Mixed Bed  ->  Terminal Filter  ->  Production Water Points

This 1 m3/h ultrapure water equipment was designed for PCB manufacturing applications. It integrates pretreatment, double-pass reverse osmosis, EDI continuous deionization, UV sterilization, ultrapure water storage, polishing mixed bed treatment, terminal filtration, and distribution to production water points.

Pretreatment for stable membrane protection

The Multi-media Filter reduces suspended solids, the Activated Carbon Filter removes residual chlorine and organics, and the Softening Water Filter with Salt Tank support reduces hardness and scaling risk. The Security Filter then captures fine particles before the first RO stage.

Double-pass RO and EDI for electronic-grade process water

The first-stage RO removes most dissolved salts and impurities, while the second-stage RO further lowers ionic load. The EDI System then provides continuous deionization, helping the equipment produce stable ultrapure water with lower chemical regeneration requirements.

Final polishing for PCB production points

UV Sterilization reduces microbiological risk, the Ultrapure Water Tank provides buffer storage, and the Water Supply System delivers water through a Polishing Mixed Bed and Terminal Filter before it reaches production water points.

After installation and commissioning, the ultrapure water equipment successfully met the PCB factory's production water requirements and provided reliable support for cleaning, rinsing, and process water use.

· Stable ultrapure water output of 1 m3/h for PCB production use.

· Improved control of dissolved salts and conductivity through double-pass RO plus EDI.

· Reduced hardness, residual chlorine, particles, and downstream contamination risk.

· Better final water quality assurance through UV, polishing mixed bed, and terminal filtration.、

· More reliable support for PCB cleaning, precision rinsing, and production line operation.

· Compact system layout suitable for small and medium electronic manufacturing facilities.

Zhongnuo Water Treatment provides customized purified water and ultrapure water systems for electronics, PCB, medical device, pharmaceutical, food, and industrial manufacturing customers. Each system is designed around feed water quality, target water quality, plant layout, and production process needs.

· Customized double-pass RO plus EDI ultrapure water system design for PCB applications.

· Integrated process planning from pretreatment through final polishing and terminal filtration.

· Compact equipment configuration for small and medium production capacities.

· One-stop support covering design, manufacturing, commissioning, and technical service.

1. Why does PCB manufacturing require ultrapure water?

Ultrapure water helps reduce ionic residue, particle contamination, and water quality variation during cleaning, rinsing, and precision process steps.

2. Why use double-pass RO and EDI for this system?

Double-pass RO provides strong desalination, while EDI further reduces ionic contaminants and supports stable ultrapure water quality with less chemical regeneration.

3. What is the role of the polishing mixed bed and terminal filter?

The polishing mixed bed further refines final water quality, and the terminal filter captures possible fine particles before water reaches production points.

4. Can this system be customized for different PCB production lines?

Yes. Zhongnuo Water Treatment can customize capacity, pretreatment, RO staging, EDI configuration, polishing steps, and distribution layout according to production process requirements.