Fuji CAC brings cleanrooms, HVAC, electrical systems and process utilities into one coordinated facility package for semiconductor, electronics and advanced manufacturing projects in Vietnam.
New facilities, rented-factory conversions, expansions and cleanroom renovations each need a defined design basis. Delivery may be an integrated Design & Build / general contractor package or a specialist scope, with responsibilities agreed for each project.
CSA & cleanroom fit-out
Civil, structural and architectural interfaces; cleanroom partitions, ceilings, finishes and coordinated people and material flows.
HVAC & process utilities
Air handling, filtration, pressure relationships and utility distribution; process gases, DI water and equipment connections within the agreed scope.
Electrical & facility controls
Power distribution, ELV, BMS/FMCS interfaces and monitoring, coordinated with installation, testing and commissioning.
Cleanroom design workflow
Cleanroom design workflow — an engineering concept, not a completed-project photograph. Open full-resolution illustration ↗Read the nine design stages
Product and process
Identify process steps, tool requirements and product-quality targets.
Contamination risks
Assess particles, AMC, ESD, heat, moisture and vibration as relevant.
User requirements
Define zones, people and material flows, utilities and safety.
Cleanliness criteria
Specify ISO class, particle sizes and occupancy state for each zone.
Design basis
Agree loads, airflow strategy, pressure relationships and resilience.
Detailed criteria
Set process-specific limits for environmental conditions and utilities.
Integrated design
Coordinate architecture, HVAC, filtration, tool exhaust and controls.
Verification
Commission, classify air cleanliness and test agreed performance.
Operation
Handover records, train operators and implement monitoring and maintenance.
Cleanroom air systems
A common configuration for semiconductor and electronics cleanrooms combines a make-up air unit (MAU), fan filter units (FFUs) and dry cooling coils (DCCs). Air returns through a perforated raised floor and the underfloor plenum, completing a controlled recirculation loop.
MAU make-up air joins the ceiling plenum. FFUs circulate air through the room, raised-floor return and DCC; process exhaust leaves separately.Outdoor air → MAU filtration and conditioning → ceiling supply plenum. Make-up air replaces exhaust and leakage losses.Ceiling plenum → FFU / HEPA or ULPA → cleanroom → perforated raised floor → return plenum → DCC → ceiling plenum.Process equipment → dedicated exhaust duct → exhaust fan → discharge / treatment as required. No connection to the room-air recirculation loop.
Illustrative airflow · Animation speeds do not represent design velocities.
MAU + FFU + DCC with raised-floor return. The final configuration is tailored to process and safety requirements. Open full-resolution illustration ↗
How the air moves
1
MAU · Condition outdoor air
The MAU filters and conditions outdoor air, including cooling and dehumidification. Make-up air is balanced against exhaust and room leakage; reheat or humidification is added when required.
2
FFU · Supply filtered air
Ceiling-mounted fan filter units draw air from the supply plenum and deliver it to the room through HEPA or ULPA filters selected for the process.
3
Raised floor · Collect return air
Air passes down through perforated floor panels into the underfloor return plenum, then rises through the side return shafts.
4
DCC · Remove sensible heat
Dry cooling coils cool the return air before it re-enters the ceiling plenum. Coil surfaces stay above the local air dew point to avoid condensation; the FFUs circulate the air again.
Engineering decisions that depend on your process
Process-specific cleanliness
Wafer fabrication, assembly, packaging and test do not share one universal cleanroom class. Assess room-level and tool-level protection separately. A mini-environment can provide local protection where justified by the process.
Environmental and ESD controls
Specify temperature, relative humidity, pressure relationships, vibration and process lighting from tool and product requirements. Establish an ESD control programme where applicable; humidity control alone does not demonstrate ESD protection. ISO particle class does not prescribe a universal ACH, pressure difference, room velocity or filter coverage.
Molecular contamination and safety
Assess AMC separately where chemicals threaten the product or process. HEPA/ULPA particulate filters do not, by themselves, demonstrate control of gas-phase molecular contaminants. Hazardous tool exhaust requires dedicated containment and compatible exhaust/treatment arrangements. Room pressure must satisfy both contamination control and safety; positive pressure is not appropriate for every space.
Verification and continued operation
Agree commissioning and acceptance tests before design freeze. Depending on scope, these can include particle classification, installed-filter leakage, airflow, pressure, temperature/humidity, airflow visualisation, recovery and safety interlocks. Monitoring follows an agreed risk-based plan. IQ/OQ/PQ may be used under the client’s qualification framework; it is not a universal semiconductor handover requirement.
Design concepts
Explore an ISO Class 5 cleanroom
See how people, materials and controlled air move through a cleanroom—from the room layout to the temperature concept.
Separate routes. A coordinated clean zone.
Personnel
Gowning → controlled personnel entry → process room
Materials
Preparation → material airlock or pass-through → process room
Exit & waste
De-gowning and controlled removal routes, coordinated with operations
Illustrative zoning: room grades, air showers, airlocks and pressure relationships are selected for the process. “Class 100” is an approximate legacy comparison to ISO Class 5 at ≥0.5 µm.
Follow the air—and the heat
A 22-second concept animation follows MAU supply, FFU downflow, equipment heat, raised-floor return and DCC cooling.
22 seconds · Silent · English on-screen labels
The displayed temperatures and room dimensions are example assumptions. This concept animation is not a validated CFD study or evidence of ISO Class 5 performance.
Read the animation sequence
The MAU supplies conditioned outdoor air to the ceiling plenum.
FFUs filter the air and direct it down into the clean zone.
Process equipment adds heat to the room air.
Warmer air returns through the raised floor.
The DCC removes sensible heat before the air returns to the ceiling plenum.
Process exhaust follows a separate discharge path.
Cleanroom particle classification
Comparison at the cumulative particle-size threshold ≥0.5 µm
ISO 14644-1
ISO limit particles/m³ at ≥0.5 µm
Legacy FS 209E English class
ISO 3
35
≈ Class 1
ISO 4
352
≈ Class 10
ISO 5
3 520
≈ Class 100
ISO 6
35 200
≈ Class 1 000
ISO 7
352 000
≈ Class 10 000
ISO 8
3 520 000
≈ Class 100 000
FS 209E was withdrawn on 29 November 2001. Its English class numbers use a particles/ft³ basis. This is an approximate crosswalk at ≥0.5 µm, not an interchangeable full classification or test method. Specify the zone, ISO class, particle size(s), occupancy state and agreed verification criteria.
Relevant experience, with a defined scope
Semiconductor facility upgrade & expansion
Design & Build of electrical infrastructure, utility distribution and CSA works, including cleanroom renovation and facility upgrades.
No. At the cumulative particle-size threshold ≥0.5 µm, ISO Class 5 is approximately comparable to legacy FS 209E Class 100, and ISO Class 6 to Class 1,000. The comparison does not replace full classification or the agreed testing method.
Does every semiconductor or electronics process need the same cleanroom?
No. Define the product, process steps, equipment and contamination risks first. The ISO particle class, occupancy state, environmental controls and utility requirements are then specified for each zone.
Can a rented factory or warehouse be converted?
Fuji CAC’s documented experience includes conversion of existing warehouses into manufacturing facilities. Feasibility depends on the building condition, available utilities, layout, process requirements and agreed scope.
What information should we send for an initial discussion?
Send the project location, available drawings, production process, cleanroom area, target class and occupancy state if known, equipment utility requirements, expected delivery scope and target schedule.
Planning a cleanroom or electronics facility in Vietnam?
Share your location, floor plan, production requirements and target schedule. Our team can discuss the facility scope, engineering interfaces and next information needed.
