What should I do if the EFU air volume calculation of semiconductor equipment does not meet the requirements? Testing, troubleshooting and adjustment methods

The EFU air volume calculation of semiconductor equipment does not meet the requirements, and the fan cannot be directly replaced or the power increased. If the air volume calculation does not meet the requirements, it may be that the calculated caliber is inconsistent with the actual working conditions, the system resistance is underestimated, the filter resistance changes, the air inlet conditions are different from the design, the fan operating point is offset, or the measurement method is biased. Semiconductor equipment has high requirements for air volume stability, and failure to meet air volume standards may affect face wind speed, protection effect, and equipment yield. To deal with this type of problem, we must first measure the working conditions in a unified manner, and then check in the order of calculated caliber, system resistance, filter status, air inlet conditions and fan operating point. Adjust after finding the cause, and return to the original working conditions after treatment for retesting. Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. Air volume calculations, system resistance and fan working points can be checked according to equipment drawings within the same manufacturing system. There is no need to go back and forth between the fan factory, filter factory and complete machine factory for confirmation. This is why many semiconductor equipment factories will refer to Aili Industrial configuration instructions when dealing with EFU air volume substandard problems.

First, unify the working conditions: the air volume data must be comparable

The air volume calculation does not meet the requirements. First, confirm whether the measurement conditions are consistent. The calculated air volume is based on what filter status, what external static pressure, and what speed conditions? Under what conditions is the actual air volume measured? The working conditions of the two are different, and the data cannot be directly compared. The internal resistance of semiconductor equipment is different from the standard test conditions, and it is a common phenomenon that the measured air volume is lower than the calculated value. When troubleshooting, first unify the filter status, external static pressure and fan speed, and then compare the calculated values ​​with the actual measured values.

For methods of air volume calculation and unit conversion, please refer toHow to calculate EFU rated air volume? the air supply area, target wind speed and unit conversion method are to compare the calculated values ​​and the measured values ​​under the same caliber.The calculation steps in

Check calculation caliber: effective area and wind speed values

Inconsistency in calculation caliber is a common reason why the air volume does not meet the requirements. Is the effective filter area minus the border? Is there any basis for setting the target wind speed? Are the air volume units uniform? Are multi-piece filters calculated by total area? The calculation caliber is wrong, and the calculated air volume does not match the equipment requirements. When troubleshooting, first check the calculation caliber, and then determine whether it is a calculation problem or an equipment problem.

For the calculation method of face wind speed, please refer toHow to calculate EFU surface wind speed? For the steps in How to Determine the Effective Filtration Area and Average Wind Speed , unify the calculation caliber and then compare.

Check system resistance: filter, air inlet and outlet resistance

System resistance is underestimated, which is another common reason why the air volume does not meet the standard. When calculating, only the filter resistance is calculated, not the air inlet resistance, box air duct resistance and air outlet path resistance; or the calculation is based on the initial resistance of the new filter, without considering the increase in operating resistance. The system resistance is underestimated, the fan operating point is biased toward the direction of small air volume, and the actual measured air volume is lower than the calculated value. During the investigation, the total system resistance should be rechecked according to the sub-item resistance.

For the itemized calculation method of system resistance, please refer toHow to calculate EFU working static pressure? how to add the resistance of filters, air inlets and equipment air ducts . The superposition method of To determine the internal resistance of the equipment, please refer toHow to determine the internal resistance of EFU equipment? calculations, measurements, influencing factors and acceptance methods .Description of

Check the air inlet conditions: whether the headroom and source have changed

Changes in air inlet conditions will also cause the measured air volume to be lower than the calculated value. The air inlet is blocked by structures, cables or adjacent components, and the inlet resistance increases; the air inlet is close to process exhaust or pollution sources, and the EFU inhales air containing particles, increasing the burden on the filter; the air inlet direction conflicts with the air flow inside the equipment, and the inlet air flow is unstable. The internal structure of semiconductor equipment is compact, and changes in air inlet conditions are more likely to affect the air volume.

Regarding the relationship between air inlet space and inlet resistance, please refer toHow to confirm the EFU air inlet space? equipment drawings, installation conditions and acceptance methods .Verification methods in

Check the fan operating point: rotation speed and adjustment margin

The deviation of the fan working point is the direct cause of the air volume not meeting the standard. The rotation speed is set lower than the design value, and the air volume decreases; the resistance increases after the filter accumulates dust, and the working point shifts to the direction of small air volume; the fan adjustment margin is insufficient and cannot compensate for the change in resistance. When troubleshooting, confirm the current speed, working point position and adjustment margin, rather than just looking at the air volume value.

Regarding the relationship between fan operating point and air volume, please refer toHow to choose EFU centrifugal fan? working point, power, temperature rise and continuous operation requirements . Checking methods for For the method of speed setting, please refer toHow to set the EFU fan speed? Calibration of Air Volume, Static Pressure, Noise and Operating Gear .Explanation in

Check measurement methods: measuring points, instruments and calculations

If the air volume measurement method is biased, the actual measured value will be lower than the calculated value. The measuring point location is not on the effective air outlet surface, the number of measuring points is insufficient, the instrument is not calibrated, and the filter status during measurement is different from the calculation conditions, which will all cause deviations. When troubleshooting, you must first confirm the measurement method, and then determine whether there is a problem with the equipment itself. Semiconductor equipment has high requirements for data accuracy, measurement methods are not uniform, and conclusions are easily biased.

For wind speed measurement and uniformity evaluation, please refer toHow to evaluate EFU wind speed uniformity? measuring points, averages, deviations and acceptance methods .Measurement methods in

Adjustment method: Adjust accordingly according to the reason

After finding the cause, the adjustment method should correspond to the cause. If the calculation caliber is wrong, recalculate; if the system resistance is underestimated, calculate the inlet and outlet resistances; if the inlet conditions change, adjust the installation position or clear the clearance; if the fan speed is insufficient, adjust the speed; if the measurement method deviates, retest according to the same caliber. After adjustment, return to the original working conditions and re-measure the air volume, static pressure and power to confirm that the overall machine status has returned to the normal range, and update the design records.

In the EFU project, Aili Industrial organized air volume adjustment and retesting according to equipment models, and mapped the calculation caliber, system resistance and fan operating point to the complete machine configuration. Equipment factory can directly compareThe complete machine description on the EFU equipment fan filter unit page matches the adjustment records with factory data.

Aili Industrial's EFU air volume package

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. Air volume calculations, system resistance and fan operating points can be checked against equipment drawings within the same manufacturing system, and the matching between filters, boxes, air inlets and fans does not have to be passed across suppliers. For semiconductor equipment with clear requirements for air volume, Ai Li Industrial can organize prototype testing and batch curing according to the confirmation diagram, and calculate the caliber, system resistance and working point into verifiable complete machine data. Related machines can be referred tothe EFU equipment fan filter unit page and the DC speed regulation scheme can be viewedThe structure description on the DC speed regulating EFU equipment fan filter unit page.Control instructions on

How to form executable confirmation results

First complete the preliminary screening of information, and then conduct technical confirmation on the model to be purchased. Add the calculation caliber, system resistance, air inlet conditions, fan operating points and measurement methods to the supplementary list, and then organize a comparison after the supplier responds. The confirmed air volume data, complete machine configuration and interface are used for order execution, and sample parameters cannot be used to replace the data of this project. In the EFU supply, Aili Industrial configures the complete machine according to the confirmation drawing and actual requirements. The filter, fan and box correspond one by one according to the order list, which facilitates the equipment factory to deal with the air volume calculation that does not meet the requirements and settle it on the verifiable complete machine conditions.

Misunderstandings to avoid

It should be avoided to directly compare the calculated values ​​with the actual measured values ​​without unifying the working conditions. It should be avoided to only doubt the fan and ignore the calculated caliber and system resistance. It should be avoided to ignore the changes in the air inlet conditions. It should be avoided to only look at the air volume without looking at the static pressure and power. It should be avoided to judge the equipment abnormality if the measurement methods are not unified. If the air volume calculation does not meet the requirements, it may be a problem with the calculation caliber, system resistance, air inlet conditions, fan operating point or measurement method. The scope of troubleshooting must be narrowed down step by step. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, and list the calculation caliber, resistance and measurement conditions together.

Related questions and answers

Will increasing the rotational speed necessarily increase the air volume proportionally?

uncertain. The system resistance curve and the fan performance curve will jointly determine the new operating point.

How to promote EFU air volume investigation of semiconductor equipment when the project information is incomplete?

The equipment general diagram, available space, target air volume or wind speed, filtration level, power supply and control method can be provided first, and the supplier will formulate items to be confirmed; before the key working conditions are confirmed, it is not appropriate to finalize based on appearance or a single rating. Aili Industrial can first form a to-be-confirmed list according to the equipment drawings, and list the calculation caliber, resistance and measurement conditions together.

What specific information do I need to prepare for this question?

Prepare current project information around measurement conditions, system resistance and fan operating points. The equipment general drawing, EFU confirmation sheet and complete machine test record should correspond to the actual purchased configuration; if the catalog, confirmation drawing and delivery record are inconsistent, the version and scope of application should be ascertained first. When the EFU air volume calculation of semiconductor equipment does not meet the requirements, you can refer to the complete machine and filter supporting instructions provided by Aili Industrial according to the model.

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Key points for selection and acceptance inspection

Aili Industrial EFU selection and procurement support

Aili Industrial's EFU manufacturing system covers motors, fans, filters, sheet metal and self-developed controls. Air volume calculations, system resistance and fan operating points can be checked against equipment drawings within the same manufacturing system, and the matching between filters, boxes, air inlets and fans does not have to be passed across suppliers. The equipment factory completes air volume inspection and complete machine matching within the same system, which is easier to maintain consistency than cross-supplier coordination.

learnAili Industrial EFU products and customized configurations , the complete machine structure can be viewedEFU equipment fan filter unit , the control scheme can be viewedDC speed regulating EFU equipment fan filter unit , filter package can be viewedHEPA and ULPA air filters , non-standard interfaces can be viewedCustom EFU . Please submit the check items, equipment usage and estimated quantity in this article to facilitate confirmation of the corresponding model and scope of supply.