What space and cleanliness requirements need to be considered when using FFU in EFEM equipment?
EFEM has different requirements for FFU than ordinary clean rooms
EFEM is the equipment front-end module used to handle wafers between the FOUP and process equipment. The interior of EFEM is a micro-environment with compact space and high requirements for cleanliness. The internal cleanliness of some EFEMs can reach ISO Class 1 level-4-10。
When using FFU in EFEM, it cannot be handled in the same way as ordinary clean room ceiling FFU. The internal space of EFEM is limited, and FFU needs to cooperate with the action range of the wafer handling mechanism, internal air circulation path and pressure control. The size, installation method and air supply direction of the FFU need to match the EFEM structure.
Therefore, when using FFU in EFEM, both space requirements and cleanliness requirements need to be considered. Aili Industrial has complete production capabilities in FFU complete machines and equipment-side supporting, and can provide ultra-thin or customized air supply solutions based on the internal structure of EFEM. For the basic structure of the FFU machine, please refer toAili Industrial FFU fan filter unit。
How to check internal clearance
The space inside the EFEM is usually occupied by wafer handling robots, guide rails, loading ports and sensors. When FFU is installed on the top or side of the EFEM, the following clearance conditions need to be confirmed: whether the height of the FFU machine matches the top space of the EFEM; the distance between the FFU air inlet and the top structure of the EFEM; the distance between the FFU air outlet surface and the highest point of the wafer handling mechanism; whether the FFU affects the robot's motion trajectory; and the operating space required for FFU maintenance and filter replacement.
The internal space of EFEM is compact, and conventional FFU may not be installed. Ultra-thin FFU or customized EFEM dedicated air supply unit may be more suitable. For applications with extremely limited space, you can refer to70mm ultra-thin EFU andCustomize the EFU equipment-side fan filter unit to understand the compact solution.
How is the air circulation path organized?
The airflow organization inside EFEM usually adopts circulation method. The FFU supplies air downward from the top of the EFEM. After the air flow passes through the wafer handling area, it returns from the bottom or side return air path and then circulates through the FFU. This circulation method can reduce the entry of external gas and maintain the cleanliness of the internal microenvironment-9。
The airflow path design needs to consider: whether the FFU air supply direction matches the wafer handling area; whether the return air path is blocked by mechanisms or cables; whether the airflow can cover key areas without generating turbulence; whether local filtration or chemical filtration is required.
If EFEM uses an inert gas environment, the air circulation system needs to be completely closed, and the FFU and return air path form a closed loop.-11。
How to correspond to cleanliness levels
EFEM internal cleanliness level requirements are usually higher. The internal cleanliness of some EFEMs can reach ISO Class 1 or Class 2 levels -4-18. This means that the filters matching FFU need to meet corresponding efficiency requirements, and sealing and installation also need to meet higher standards.
The efficiency level, sealing method and installation quality of the FFU filter directly affect the internal cleanliness of the EFEM. The factory leak test of the filter is only the basis, and the sealing integrity after installation also needs to be confirmed. For details, please refer toIf the FFU filter element passes the leak test, why should the installation seal be checked (Note: This link is an example of the filter product page, please refer to the corresponding page on the site for specific content).
How to cooperate with pressure control
Positive pressure is usually maintained inside the EFEM to prevent unfiltered air from entering -16. The balance of FFU supply air volume and return air volume determines the internal pressure. If the FFU supply air volume is greater than the return air volume, a positive pressure will be formed inside. If the return air is not smooth, the pressure may rise.
The pressure relationship between EFEM and FOUP also needs to be confirmed. When the FOUP is turned on, the internal pressure of the EFEM should be slightly higher than the internal pressure of the FOUP or maintain an appropriate relationship to prevent particles from entering the EFEM from the FOUP, or from the EFEM entering the FOUP.-3。
How to consider vibration and noise
EFEM contains precision wafer handling robots. Vibration during FFU operation may affect robot positioning accuracy or wafer handling stability. If the FFU is mounted directly on the EFEM structure, vibrations may be transmitted to the robot.
Vibration reduction measures can consider vibration-absorbing pads, flexible installation or choosing low-vibration fans. If EFEM has higher vibration requirements, the FFU vibration data and installation method can be confirmed during the selection stage.
How to reserve maintenance space
The FFU inside the EFEM requires regular maintenance, including filter replacement and fan inspection. Maintenance space needs to be reserved during the design phase. If the FFU is installed on top of the EFEM, filter replacement requires access from the top. If there is insufficient space, it may be necessary to design a detachable structure or a lateral maintenance method.
The drop-down FFU allows filter replacement from one side of the unit, reducing the need for top access. Related structures can be referred toDetachable FFU knows how to maintain it.
Issues that should be confirmed in advance during project communication
In the design stage of the EFEM equipment FFU solution, it is recommended to confirm the following with the FFU manufacturer and equipment side: EFEM internal clearance size; wafer handling mechanism movement range; FFU installation location and method; air flow circulation path; target cleanliness level; pressure control requirements; vibration and noise requirements; maintenance space and method; whether an inert gas environment is required; whether chemical filtration is required.
If you are selecting FFU or EFU for your EFEM device, you can visitAili Industrial FFU fan filter unit to learn about the complete machine configuration, you can also refer to70mm ultra-thin EFU andCustomize the EFU equipment-side fan filter unit to learn about the equipment-side compact solution, or contact Aili Industrial to obtain EFEM supporting support.
in conclusion
When using FFU in EFEM equipment, both space and cleanliness requirements need to be considered. Internal clearance, air circulation paths, cleanliness levels, pressure control, vibration and maintenance spaces are all conditions that need to be checked. The internal space of EFEM is compact, which may require ultra-thin or customized FFU solutions. The requirements for cleanliness levels are relatively high, and filters and installation seals need to meet corresponding standards.
Aili Industrial has complete production capabilities in FFU complete machines and equipment-side supporting, and can provide ultra-thin or customized air supply solutions based on the internal structure of EFEM. If you need to know more about EFEM equipment FFU application, you can visitAili Industrial FFU fan filter unit , you are also welcome to contact Aili Industrial for project support.
