How to choose EFU when using EFEM? Air volume, filtration and space matching in wafer transfer area

The interior of EFEM contains a wafer transfer mechanism, loading port and various structural parts. The air flow is easily affected by manipulators, frames and cables. EFU should be arranged around the exposed and moving areas of the wafer, and test points should be used to verify whether the clean air truly covers key locations.

Determine protected areas and contamination pathways

In conjunction with the wafer's path from loading to transport, possible particle sources, openings and reflow areas are identified. The EFU air outlet surface should try to cover the critical path and avoid bringing in air from non-clean areas.

Calculate air volume based on effective area and target wind speed

First estimate the required air volume, and then add the filter and equipment structural resistance. Wind speed distribution should be measured at typical positions of the manipulator, not just air-gauge equipment.

Head space determines structural plan

There are often guards, wire troughs and control components on the top of EFEM. If the conventional height cannot be installed, the ultra-thin or small-sized EFU can be evaluated, and the overall height, air inlet space, connectors and maintenance direction can be confirmed in the drawings.

Filtration and sealing are determined according to project standards

The filtration efficiency can be selected as H14 or higher, but it must match the target air volume, fan residual pressure and leak detection method. The filter frame and EFU installation interface should avoid bypass air leakage.

Control logic cooperates with EFEM status

EFU can adjust speed or start and stop according to the device's power-on, standby and maintenance status. The control strategy should avoid the EFU still being in low gear when the equipment enters the process state, and define a safe state after a fault or communication interruption.

Maintain design to avoid contamination of critical areas

When disassembling and assembling filters and fans, particles should be reduced from falling into the transfer area. The maintenance direction can be determined based on the equipment door opening direction, maintenance space and replacement process.

FAQ

What should I do if there is insufficient head space in EFEM?

Ultra-thin or split small size solutions can be evaluated, but air volume, uniformity and maintenance must be verified simultaneously.

Will the movement of the manipulator affect the wind speed?

meeting. Movement and dwell positions will change local resistance and airflow and should be included in the test.

Does EFEM need centralized control when using EFU?

Depending on the number of devices and linkage requirements, a single machine can be controlled locally, while multi-unit or batch devices are more suitable for unified interface management.

How does Aili Industry configure EFU for EFEM?

EFEM is an important transfer area before wafers enter the process equipment. EFU configuration needs to pay attention to the clean air coverage, air flow stability and wind speed uniformity of the wafer transfer space. The selection should be based on the EFEM head space, internal structure, manipulator movement area, filtration efficiency and target air volume.

The EFU air supply surface needs to cover the main transmission area while preventing local airflow from being blocked by the frame, cables or other components. If the top height of the equipment is limited, the EFU box, filter, air inlet space and inspection distance must also be considered comprehensively, rather than just comparing the nominal height of the product.

Aili Industry can configure ultra-thin EFU, small-size EFU or non-standard equipment-side EFU based on the EFEM structure diagram, and match DC fans, control systems and high-efficiency filters. During the prototype stage, wind speed distribution can be measured based on actual equipment to confirm air supply coverage and operating parameters.

Related content

EFU FAQ and technical support EFU equipment fan filter unit 70mm ultra-thin EFU

Conclusion: EFU used in EFEM should protect areas related to wafer transfer and loading. Selection needs to evaluate the head space, manipulator shielding, target wind speed, filter resistance, return air path and control interface in the same equipment diagram.