How to configure the etching equipment EFU? Corrosive environment, local air supply and maintenance conditions confirmation

Direct answer: When configuring EFU for etching equipment, you should first identify the clean areas that need to be protected, and then determine the air volume, static pressure, filtration efficiency, box material, and control interface of the EFU based on process exhaust, internal pressure relationships of the equipment, potential corrosive environments, installation space, and maintenance methods.

The main function of EFU is to provide filtered clean air to the wafer transfer area, robot activity area or other particle-sensitive areas. It cannot replace the process exhaust system of etching equipment. When selecting, it is necessary to avoid clean air supply from interfering with the negative pressure of the process chamber, and to prevent corrosive gases from entering the EFU and affecting the use of fans, motors, filters and control components.

Why does etching equipment need to be configured with EFU?

The interior of etching equipment usually contains different functional areas such as process chamber, wafer transfer, manipulator, loading interface and exhaust system. The contamination risks faced by each area are not the same, so EFU cannot be simply configured according to the top area of ​​the equipment.

The device-side EFU is mainly responsible for the following tasks:

• Provide local clean air supply for wafer transfer and temporary storage areas;

• Reduce the impact of particles caused by equipment opening, maintenance or material transfer;

• Help key areas form a relatively stable airflow direction;

• Cooperate with the internal return air or exhaust path of the equipment to control the spread of pollution;

• Adjust the air volume for work, duty or maintenance according to the operating status of the equipment.

Before configuration, the area to be protected, the allowed air supply direction, and the process location that cannot be interfered by airflow should be marked in the equipment drawings.

EFU clean air supply cannot replace process exhaust

EFU and process exhaust have different functions:

If the EFU air supply volume is too large or the air supply direction is unreasonable, the original pressure relationship in the process area may be changed. On the contrary, if the exhaust volume of the equipment is too large, the effective air supply range of the EFU may be reduced, or even untreated surrounding air may be sucked into key areas.

Therefore, the EFU air volume cannot be determined independently from the equipment exhaust parameters. During design, the supply air, return air and exhaust air should be analyzed in the same air flow diagram.

How to determine the installation location of etching equipment EFU

The EFU installation location should be determined around the cleanliness protection goal, rather than being installed wherever there is space. Usually you need to focus on checking the following locations:

• The wafer enters the loading area of ​​the equipment;

• Wafer transfer and robot activity areas;

• Detection or positioning locations that are sensitive to particles;

• Areas that are easily affected by outside air when the equipment is opened or maintained;

• A clean and isolated space is required around the process chamber.

The EFU air outlet surface should try to cover the area that needs to be protected, while avoiding manipulators, beams, cable trays and large areas of sheet metal. Sufficient space should also be reserved on the air inlet side to avoid a decrease in actual air volume due to obstruction of the suction inlet.

When the installation height is limited, the internal dimensions of the equipment can be evaluated70mm ultra-thin EFU ; if the standard specifications cannot fit the equipment opening, air inlet direction or maintenance path, you need to useCustomized EFU to rematch cabinet size and interface.

How should air volume and static pressure be determined?

The air volume of the etching equipment EFU should be determined based on the effective air supply area, target average wind speed and internal air flow organization of the equipment. The following relationship can be used for preliminary estimation:

Target air volume = effective air supply area × target average wind speed

The effective air supply area here is not the external area of ​​the EFU box, but the actual air outlet area after deducting the filter frame, equipment frame and other obstructions.

After completing the preliminary air volume calculation, check the following resistance:

• EFU air inlet and protective structure resistance;

• Fan cavity and internal air duct resistance;

• HEPA or ULPA filter resistance;

• Resistance from air outlet orifice plates, flow distribution structures or equipment grilles;

• Resistance caused by local passages and structural obstructions inside the equipment;

• Changes in filter resistance after use for a period of time.

The target air volume and total resistance together constitute the actual operating point of the EFU. Selecting an EFU based only on the rated air volume may result in differences between the actual air volume after installation and the design value.

Filtration efficiency should be determined according to process requirements

The etching equipment EFU can be equipped with corresponding levels of high-efficiency or ultra-high-efficiency filters according to project cleanliness goals, customer technical specifications and particle control requirements. The higher the filtration efficiency, the more attention usually needs to be paid to filter resistance, effective area and fan static pressure capacity.

It is recommended to make clear synchronization when selecting:

• Filter efficiency rating;

• Target particle size and testing requirements;

• Initial resistance at rated air volume;

• The sealing method between the filter and the box;

• Whether leak detection is required on site;

• Filter replacement direction and disassembly and assembly space;

• The range of resistance changes allowed during use.

Filter grade alone does not determine cleaning effectiveness. Internal equipment airflow direction, local occlusion, seal integrity and exhaust relationships also affect particle control in critical areas.

What materials need to be inspected in corrosive environments

Etching equipment may involve process environments with corrosion risks, but whether the EFU will be exposed to relevant gases needs to be judged based on the actual equipment structure. Just because the equipment belongs to the etching process, it cannot be directly determined that a certain box material must be used.

Materials assessment should be combined with:

• Types and concentrations of gases that the EFU installation area may be exposed to;

• Air flow direction during normal operation, shutdown and maintenance conditions;

• ambient temperature and humidity;

• Box, fasteners and bracket materials;

• seals and cable materials;

• Filter media, frame and sealant;

• Protection conditions for motors, controllers and connectors.

If the EFU is located in a relatively independent clean air supply area and will not come into contact with process gases, the conventional structure may already meet the project requirements; if there is a risk of corrosive gas backflow or long-term exposure, the corresponding box, fasteners, seals and electrical protection methods should be selected according to the customer's material specifications.

Will EFU affect the negative pressure of the process chamber?

This possibility exists and therefore needs to be verified during the design and debugging phases.

When the EFU air supply volume, equipment return air volume and process exhaust air volume do not match, the local pressure inside the equipment may be changed. To determine whether the EFU affects the negative pressure of the process chamber, you can follow the following steps:

1. Mark the locations of the EFU air outlet, process exhaust outlet and equipment return air outlet;

2. Record the exhaust air volume under different operating conditions of the equipment;

3. Check whether the EFU air supply blows directly to the process cavity or exhaust outlet;

4. Measure differential pressure and wind speed in critical areas;

5. Adjust the EFU speed in stages and observe the pressure relationship and air flow direction;

6. Determine the operating gear under normal production, duty and maintenance conditions;

7. Write the final speed, air volume and linkage logic into the device parameters.

For equipment with complex airflow boundaries, the actual flow direction can be confirmed through smoke observation, wind speed measurement, pressure difference testing or other methods approved by the equipment.

How to link the control system with etching equipment

The EFU of etching equipment usually needs to match the operating status of the equipment, rather than maintaining a single rotation speed for a long time. According to project needs, you can set:

• The working gear of the equipment during production;

• Duty position in standby state;

• Operating mode during door opening or maintenance;

• Logic to shut down or keep running when equipment is abnormal;

• Speed ​​adjustment after filter resistance changes;

• Local speed regulation, analog control or communication control;

• Running status and fault signal feedback.

When using multi-speed speed regulation, the air volume, wind speed, power, noise and pressure status of each gear should be recorded separately. Following proven parameter settings during series production can reduce airflow differences between different devices.

Why should maintenance paths be confirmed during the design stage?

Filters, fans and control components all require maintenance space. If the disassembly and assembly direction is considered after the equipment is installed, problems may arise such that the filter cannot be removed, the connector cannot be operated, or other equipment structures need to be dismantled for maintenance.

The design stage needs to clarify:

If the maintenance process may come into contact with process residues, the equipment owner should develop corresponding shutdown, isolation and safe handling procedures. EFU suppliers mainly cooperate to confirm structural interfaces, component disassembly and assembly, and clean air supply recovery conditions.

Etching equipment EFU project confirmation list

How Aili Industry cooperates with the etching equipment EFU project

The etching equipment EFU needs to deal with clean air supply, equipment exhaust, corrosion risks and limited installation space at the same time. Usually, the selection cannot be completed relying on only one standard air volume parameter.

Aili Industrial can cooperate to confirm the EFU size, air inlet and outlet direction, fan working point, filter efficiency, box structure and control interface based on the equipment drawings and target area. Relying on the supporting R&D and production of motors, fans, control systems, sheet metal structures, air filters and complete machine assembly, the structure and operating parameters can be adjusted according to the actual equipment interface during the prototype stage.

When confirming the project, it is recommended to provide the internal length, width and height of the equipment, EFU installation location, process exhaust volume, target air supply area, air volume or wind speed requirements, filtration efficiency, power supply and communication method. For side air intake, ultra-thin, small size or special material structures, batch drawings can be solidified after confirmation through prototype assembly and multi-working condition testing.

Specific specifications can be found atView it in the Aili Industrial EFU product category catalog ; please refer to non-standard sizes, special air inlet methods or equipment interfaces.Custom EFU . More selection, installation and maintenance questions can be found inContinue to check out EFU FAQs and technical support .

FAQ

Can etching equipment EFU replace process exhaust?

cannot. EFU is mainly used to provide filtered clean air, and process exhaust is responsible for discharging process gas, heat or pollutants. The functions and safety requirements of the two systems are different.

Does the etching equipment EFU have to use a stainless steel box?

uncertain. Whether stainless steel or other materials are required should be determined based on the actual installation area of ​​the EFU, the gases it may be exposed to, humidity, cleaning methods and customer material specifications.

Is the higher the EFU wind speed, the better?

no. Excessive wind speed may interfere with the internal pressure relationship of the equipment or create local turbulence. The air volume should be determined around the area to be protected and confirmed by testing wind speed, pressure differential and air flow direction.

Should I choose H14 or ULPA for EFU filter?

It should be determined based on the equipment particle control objectives, customer specifications, filter resistance and fan operating point. Higher filtration efficiency does not mean that sealing, air flow organization and actual leak detection can be ignored.

How to configure EFU when there is insufficient space in the etching equipment?

Ultra-thin, small size, narrow body or side air inlet structures can be evaluated, but the filter area, air inlet resistance, air volume static pressure, temperature rise and maintenance space need to be rechecked, and the box size cannot be reduced.

in conclusion

The core of the EFU configuration of etching equipment is to provide stable and verifiable clean air for designated particle-sensitive areas without interfering with the relationship between process exhaust and equipment pressure.

Project selection should sequentially confirm the clean protection area, air supply and exhaust boundaries, target air volume and static pressure, filtration efficiency, corrosive environment, installation interface, control linkage and maintenance path . For equipment with complex airflow or limited space, the final parameters should be determined through prototype assembly and actual working conditions testing, rather than directly applying general EFU specifications.