Why they resist removal
Weakly polar and barely ionised, organics slip past resin and CEDI. They must first be converted into ions before the downstream stages can act on them.
Home / Semiconductor UPW
12 CMH UPW System
Semiconductor-grade
ultrapure water
Configured to the source water and the process it feeds. From pre-treatment to 20 nm final ultrafiltration, carried throughout in semiconductor-grade PVDF / PFA piping with seamless fusion welds.
18.2 MΩ·cmResistivityat 25 °C
< 1 ppbTOCTotal organic carbon
< 1 pptHeavy MetalsMetal ions
20 nmParticleFinal UF rating
Process Flow
A six-stage treatment train
Configured to source water and process demand — each stage exists to solve what the stage before it leaves behind.
01
Pre-treatmentPre-treatment
Removes solids, residual chlorine, organics and hardness to protect the membranes.02
Reverse Osmosis2-Pass RO
Two passes strip the great majority of dissolved salts and organics.03
CEDIElectrodeionization
Continuous deionization with no acid-alkali regeneration.04
UV Photolysis185 nm TOC
185 nm photons generate hydroxyl radicals that break organics apart.05
MBP PolisherMixed-Bed
Semiconductor-grade mixed-bed resin captures the remaining ionic fragments.06
Final UFFinal Ultrafiltration
The last barrier before the point of use, rated to 20 nm.UPW specification
- Resistivity≥ 18.2 MΩ·cm @ 25°C
- Total organic carbon< 1 ppb
- Heavy metal ions< 1 ppt
- Particle20 nm rated filtration
- Capacity12 m³/h (12 CMH)
- PipingPVDF / PFA semiconductor grade
- Supply24 h continuous
Capacity and specification scale to process demand
Piping & Materials
The specification is
won or lost in the piping
Ultrapure water is an aggressive solvent. However well the front of the system performs, leaching pipework or a weld with a dead leg will degrade the water before it reaches the point of use. Yeson carries the entire system in high-purity semiconductor-grade PVDF and PFA, joined by seamless fusion welding that removes the contamination path at source.
- Semiconductor-grade PVDF / PFALow extractables and high chemical resistance, suited to trace-metal and TOC specifications.
- Seamless fusion weldingNo internal seam and no dead leg — nothing for contamination or microbes to hold on to.
- SUS316L / BPE for pharmaceutical projectsOrbital welding ensures the integrity of every joint.
Technology 01
The TOC problem in a UPW system
Organic compounds are among the hardest contaminants to remove from a UPW system. They are weakly polar, very small and barely ionised, which leaves conventional ion exchange and electrodeionization with limited purchase on them.
What advanced nodes demand
Advanced semiconductor processes require TOC below 1 ppb while resistivity stays above 18.2 MΩ·cm — both conditions at once.
Photolysis and oxidation
A specific UV wavelength breaks the water molecule apart, producing highly oxidising hydroxyl radicals that reduce organics to ionic form for the downstream resin to capture.
185 nm photolysis
High-energy 185 nm photons are absorbed directly by the water molecule, splitting it to release highly reactive, very short-lived hydroxyl radicals:
H₂O + hν (185 nm) → H• + OH•
The amount of 185 nm light the water absorbs is the single most important determinant of TOC destruction efficiency.
Chain oxidation of organics
Hydroxyl radicals attack the bonds in organic molecules, progressively reducing them to small charged ions, carbon dioxide and water:
Organics + OH• → CO₂ + H₂O + Ions
The resulting ionic species are then fully captured by mixed-bed ion exchange or CEDI.
CO₂ removal
Some organics are oxidised all the way to carbon dioxide, which mildly acidifies the water. A degasifier membrane module downstream of the UV unit removes it efficiently.
Capturing ionic fragments
More resistant molecules break into charged fragments, which temporarily depress resistivity. High-purity mixed-bed resin or CEDI downstream removes them completely.
Reaching the theoretical limit
With UV and ion exchange working together, the water reaches the theoretical limit of 18.2 MΩ·cm (Type 1 UPW), free of interfering ions.
Technology 02
Why dissolved gases must go
Air is roughly 79% nitrogen and 21% oxygen, and gases dissolve into water the moment it meets air. At ambient temperature and pressure a glass of water holds about 8.5 ppm dissolved oxygen.
Semiconductor
Residual oxygen oxidises the circuit
A wafer is rinsed 40 to 50 times in high-purity water; oxygen left in that water oxidises the metal in the microcircuit and creates defects.
Power generation
Dissolved oxygen corrodes turbine blades
As high-pressure steam drives the turbine, dissolved oxygen oxidises and corrodes the metal, damaging blades and eroding generating efficiency.
Conductivity control
CO₂ forms carbonic acid
Surface water dissolves calcium and magnesium carbonates, generating hardness ions and carbonic acid that raise conductivity.
Technology 03
Removing particles
at the nanometre scale
At advanced nodes a single 20 nm particle is enough to cause a defect. Conventional filtration cannot work at that scale, which is why a final ultrafiltration stage sits immediately before the point of use.
Yeson uses a hollow-fibre UF module as that final barrier, intercepting both nanoscale particles and any resin fines that might shed — the last line of defence in the whole system.
- Typical requirement≥ 0.050 μm / 50 nm < 2 counts/mL
- Advanced processes0.020 μm / 20 nm
Monitoring & Verification
Quality shown as data
The system carries online TOC, SiO₂, particle, dissolved-oxygen and resistivity measurement, logging product quality continuously. Alarms raise deviations early — before they reach the production line.
Before handover we work with the customer through trace heavy-metal, boron and particle verification, and supply the complete construction and validation documentation.
TOCSiO₂ParticleDOResistivityDQ / IQ / OQ
Track Record
Already running on the hardest lines
Founded in Taipei
More than forty years planning, installing and maintaining pure-water systems.
Delivered to a top-3 equipment maker
A UPW system delivered to one of the world's three largest semiconductor equipment makers, accepted on verification.
Semiconductor-grade piping
PVDF / PFA piping with seamless fusion welding that rules out secondary contamination.
Plan your UPW system
Tell us the specification and the capacity
We will come back with a recommended treatment train, piping selection and an outline plan based on your source water.