How to configure advanced packaging equipment EFU? Key points of clean area, air volume filtration and equipment interface

The EFU configuration of advanced packaging equipment and the traditional clean room ceiling FFU are two sets of logic. The FFU tube on the ceiling refers to the number of air changes in the large space, and the EFU tube on the equipment side refers to the local microenvironment on the movement path of the wafer or substrate inside the equipment. Advanced packaging processes—hybrid bonding, formic acid reflow soldering, and flip-chip soldering—are not much more tolerant of particulate and molecular contaminants than the previous process, but the Z-axis space left for the purification module inside the equipment is often only a few tens of millimeters. When configuring EFU, you must first clearly define the clean areas inside the equipment, then select the type according to the air volume and filtration level of each area, and finally confirm whether the interfaces of the EFU and the equipment main control, air duct and installation interface can be aligned. Ai Li industrialThe 70mm ultra-thin EFU is specially designed for device-side micro-environments such as EFEM and Load Port. It supports filter levels from H13/H14 to U15/U16 and RS485/Modbus control interface. It can check the complete machine configuration according to the equipment drawings in a limited space.

Clean area: first draw boundaries, then determine levels

Cleanliness requirements within advanced packaging equipment are not uniform. The working area cleanliness of the hybrid bonding machine can reach ISO level 3. The EFU configuration of the formic acid reflow soldering equipment is marked with H14 efficiency, adjustable wind speed, and communication function. Different process sections have different requirements for particles and AMC, and EFU cannot be one-size-fits-all for the whole machine.

Before configuration, the interior of the equipment should be divided into three types of areas: the wafer/substrate exposed area (internal EFEM, Load Port interface, bonding workbench) requires the highest cleanliness level and stable laminar flow; the transmission mechanism area (robot stroke, guide rail) needs to suppress the diffusion of particles caused by movement; the periphery of the process chamber (near reflow soldering, placement head) may need to deal with molecular pollutants generated by the process itself. The number of EFUs, installation location and filtration level in each area should be confirmed separately, rather than evenly distributed according to the equipment outer area.

Ai Li IndustrialThe application scenarios of the 70mm ultra-thin EFU clearly cover the micro-environments of semiconductor equipment such as EFEM, Load Port, and wafer sorters. It supports the optional PTFE boron-free ultra-fine filter to cope with the sensitive needs of advanced processes for boron pollution.

Air volume and filtration: 'enough' on the equipment side is more difficult than 'large'

The difficulty in selecting the air volume of the equipment-side EFU is not the maximum value, but the uniformity and stability at the target wind speed . The EFU air outlet surface inside advanced packaging equipment is often close to the wafer path, and uneven wind speeds will directly translate into local turbulence or particle deposition. Aili Industrial 70mm EFU supports stepless adjustment of surface wind speed from 0.35 to 0.45 m/s, and the airflow uniformity on the outlet surface is controlled according to the requirements of the equipment. For processes such as formic acid reflow soldering, EFU also needs to maintain stable filtration efficiency in corrosive atmospheres or high temperature environments. H14 level is a common starting point. For the calculation method of filter area and face wind speed, please refer toHow to calculate EFU surface wind speed? How to determine the effective filtration area and average wind speed .

The selection of filtration level should distinguish between particle and AMC lines. Particle filtration determines H13/H14 or U15/U16 according to the process section; AMC control requires additional confirmation of the filter type. Traditional glass fiber filter paper may release boron, posing a risk of contamination to the bonding interface in advanced packaging. PTFE boron-free filter is an option. If the equipment process involves organic volatiles or acidic gases, a chemical filter needs to be configured outside or within the EFU. However, this will increase wind resistance, and the fan operating point must be rechecked during model selection. For filter matching types, please refer toHEPA vs. ULPA Air Filters .Instructions in

Key actions for air volume verification : Don’t just look at the rated air volume on the EFU sample. Suppliers are required to provide wind speed distribution data on the air outlet surface under target installation conditions (including filters and internal back pressure of equipment). The air outlet side of the EFU inside the equipment often faces the robotic arm or carrier platform. The back pressure is different from that of an open platform, and the rated air volume may drop by more than 20% in the equipment.

Equipment interface: three interfaces: electrical, air duct and installation

The biggest difference between device-side EFU and general FFU is the interface. The universal FFU is installed according to the ceiling keel and controlled by the wall switch; the equipment-side EFU must be embedded in the equipment sheet metal, connected to the equipment PLC, and connected to the equipment air duct. When configuring, you need to confirm the three interfaces one by one.

Electrical interface . The EFU's speed setting and status feedback need to be linked to the equipment main control. Ai Li IndustrialThe 70mm ultra-thin EFU supports RS485/Modbus protocol and can realize linkage and group control with the equipment PLC. The control scheme can be referred toDC speed regulating EFU equipment fan filter unit . Instructions in What needs to be confirmed is: whether the EFU accepts 0-10V or Modbus speed commands, whether the fault alarm is output through dry contacts or communication methods, and whether the equipment main control can read the actual speed of the EFU and the filter pressure difference. If the equipment requires the EFU to start in advance before the wafer enters the work area and to delay the shutdown after the process is completed, whether these timing logic should be controlled by the equipment PLC or the EFU itself should be clarified during the configuration stage.

Air duct interface . The EFU inside the equipment often does not supply air independently, but cooperates with the equipment air duct or return air path. Aili Industrial SupportCustomized EFU side air inlet/side air outlet structure, flange interface and equipment air duct are directly connected. It is necessary to confirm: the connection method between the EFU air outlet and the equipment air duct (flange size, sealing method), whether the return air path passes through the EFU air inlet side, and whether there is sufficient return air space inside the equipment. If the EFU is installed in a closed cavity, the inlet air temperature may be higher than the ambient temperature of the workshop. When selecting, the actual inlet air temperature in the equipment must be used to check the motor temperature rise.

Install the interface . Advanced packaging equipment is sensitive to micro-vibration, and the mounting rigidity of the EFU directly affects the bonding accuracy.The mounting ears and fixing points of the 70mm ultra-thin EFU need to correspond to the structural ribs of the equipment panel to prevent the fixing points from falling in the middle of the thin plate and causing local vibration. Aili Industrial's ultra-thin EFU uses a customized brushless DC motor and a high-precision dynamically balanced aluminum alloy wind wheel to reduce the risk of vibration being transmitted to precision optical devices or wafer stages. When confirming the installation interface, the fixed point position, equipment panel thickness and reinforcement method should be included in the equipment drawings for verification. The vibration transmission path verification method can be referred toHow to control vibration of ultra-thin EFU? vibration sources, installation rigidity and equipment side resonance check .Instructions on

Prototype and batch: Verification sequence of device-side EFU

The EFU configuration of advanced packaging equipment cannot be skipped through the prototype stage and directly batched. What the prototype needs to verify is not the rated parameters of the EFU unit, but the actual performance after being installed in the equipment : wind speed distribution on the wafer path, continuous operation stability under the condition of internal temperature rise of the equipment, whether the interlocking action of the EFU and the main control of the equipment is correct, and whether the vibration superposition when multiple EFUs are running at the same time is within the acceptable range. The confirmed EFU model, control parameters and installation interface are solidified into the equipment BOM. The batch EFU corresponds to the equipment drawings and prototype records one by one. Sample parameters cannot be used to replace the data of this project.

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. For related complete machines, please refer toAccording to the structural description on the EFU equipment fan filter unit page, ultra-thin models can organize prototype verification and batch curing according to equipment drawings, and archive wind speed distribution, temperature rise and vibration data with confirmation drawings, which facilitates equipment manufacturers to complete prototypes and batches in the same manufacturing system. It is easier to maintain version consistency than cross-supplier coordination.

How to generate executable configuration verification results

First confirm the division of clean areas inside the equipment and the target wind speed in each area, and then ask the supplier to provide the wind speed distribution data, Modbus point table and installation interface diagram under back pressure conditions within the equipment for the ultra-thin model to be purchased. Add the clean area, filtration level, electrical point table, air duct flange and installation fixing points to the supplementary list, and then organize the comparison after the supplier responds. The confirmed EFU configuration corresponds to the equipment BOM, and sample parameters cannot be used to replace this project data. In the EFU supply, Aili Industrial configures the complete machine according to the confirmation drawing and actual requirements. The fan, filter, box and control correspond to each item in the order list, which facilitates the equipment factory to configure the EFU configuration of the advanced packaging equipment to the verifiable complete machine conditions.

Misunderstandings to avoid

It should be avoided to evenly distribute EFU according to the outer area of ​​the equipment without dividing the clean area. It should be avoided to use the rated air volume of the open bench to replace the air volume under the back pressure condition inside the equipment. It should be avoided to only confirm 'support communication' without checking the Modbus point table and start-stop timing. It should be avoided to ignore the amplification effect of the equipment panel rigidity on the EFU vibration, and it should be avoided to skip the prototype and directly batch. The core of the EFU configuration of advanced packaging equipment is not 'to fit it in and have enough air volume', but to form a verifiable closed loop between clean area, air volume filtration and equipment interface.

Related questions and answers

The internal space of advanced packaging equipment is only 80-100mm. How to choose EFU?
Prioritize checking the total height of the EFU including the filter. Ai Li IndustrialThe cabinet thickness of the 70mm ultra-thin EFU is 70mm (excluding the filter part), leaving space for filter installation and air ducts on the Z-axis of the equipment. If the space is tighter, you need to confirm whether it accepts side air inlet structure or non-standard flange to reduce the installation height.

What special requirements does hybrid bonding equipment have for EFU?
The cleanliness of the hybrid bonding work area can reach ISO level 3, and the EFU needs laminar flow protection covering the wafer bonding interface. At the same time, bonding equipment is extremely sensitive to micro-vibrations, and the motor balance and installation rigidity of the EFU need to be confirmed more prioritized than the air volume. AMC needs to pay attention to whether the filter contains boron.

Can the EFU's Modbus interface communicate directly with my equipment's PLC?
The hardware is usually ok, but you need to check three things: whether the communication parameters of the EFU (baud rate, check digit, slave address) are configurable, whether the register address table is provided with the product, and whether the fault code definition is clear. Only writing 'Support Modbus' without providing the EFU of the point table will consume extra man-hours in the debugging phase during integration.

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Key points for selection and acceptance inspection

Aili Industrial EFU selection and procurement support

Ai Li industrialThe 70mm ultra-thin EFU is specially designed for the micro-environment of semiconductor equipment, covering EFEM, Load Port, wafer sorting, bonding equipment and other scenarios. It supports H13/H14 to U15/U16 filter levels, RS485/Modbus control, side air inlet/outlet customization and PTFE boron-free filter options. The equipment factory can check the EFU installation space, air duct interface and control point table according to the equipment drawings, and solidify the prototype verification data and batch configuration together.

Learn about Aili Industrial EFU products and customized configurations. Check out the compact models.70mm ultra-thin EFU , the entire machine structure can be viewedEFU equipment fan filter unit , non-standard interface can be viewedCustomized EFU , control scheme can be viewedDC speed regulating EFU equipment fan filter unit , filter package can be viewedHEPA and ULPA air filters . Please submit the clean area division, installation space size and estimated quantity of the equipment to facilitate confirmation of the corresponding model and interface configuration.