Vacuum Pump Stop Control for Deposit-Aware Motor Reactivation

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Solution Overview

Problem

In semiconductor manufacturing, vacuum pumps face issues with solidified or liquefied products accumulating during operation, leading to pump activation failures and prolonged manufacturing suspensions due to the need for frequent maintenance or replacement, as existing control methods fail to completely eliminate these deposits and identify faulty pumps effectively.

Innovation Solution

A control device and system that uses a decision unit to analyze past state quantities and normal fluctuation ranges of a vacuum pump's load during stop processes, adjusting motor control methods based on comparisons to prevent deposit accumulation and facilitate reactivation, including changing motor output, rotation direction, and ON/OFF periods to manage the accumulation of reaction products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the vacuum pump operates continuously to maintain manufacturing processes, then productivity is improved, but solidified or liquefied products accumulate in the pump, leading to activation failures and requiring frequent maintenance

Engineering Contradiction:
Improvecontinuous operation capabilityVSAvoidpump activation reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The control device performs preliminary actions by analyzing state quantities before the pump stops and detecting potential deposit accumulation issues before they cause activation failure. This allows preventive maintenance scheduling and avoids unexpected pump failures during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device implements feedback by continuously monitoring state quantities during pump operation and using this information to detect deposit accumulation trends. This feedback mechanism enables early warning of potential activation failures and allows for timely maintenance intervention.

Inventive Principle:
Principle #23Feedback

2Reliability

If the vacuum pump is stopped for maintenance to remove deposits, then reliability is improved, but manufacturing processes are suspended, reducing productivity

Engineering Contradiction:
Improvepump activation reliabilityVSAvoidmanufacturing process continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control device performs preliminary analysis of state quantities to predict when deposit accumulation will reach critical levels. This allows scheduling maintenance during planned downtime rather than unexpected failures, and enables proactive removal of deposits before they cause activation failure.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control device enables self-service by automatically detecting deposit accumulation trends and predicting maintenance needs based on state quantity analysis. This reduces the need for frequent manual inspections and allows maintenance to be performed only when necessary.

Inventive Principle:
Principle #25Self-service

3Ease of repair

If existing control methods are used to stop the rotor after rotating in normal and reverse directions, then some deposit removal is achieved, but deposits cannot be completely eliminated and pump activation failures still occur

Engineering Contradiction:
Improvedeposit removal capabilityVSAvoidpump activation reliability
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The control device implements enhanced feedback by continuously monitoring state quantities during rotor rotation and using this information to detect deposit accumulation patterns. This feedback enables more effective reverse rotation strategies and timing to remove deposits that existing methods miss.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control device applies parameter changes by analyzing state quantities to determine optimal reverse rotation timing, duration, and speed based on detected deposit accumulation patterns. This adaptive approach improves deposit removal effectiveness compared to fixed timing patterns.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If the vacuum pump operates at high temperature to prevent liquefaction, then reliability is improved, but compressive heat is generated during gas transfer, requiring external heating and increasing energy consumption

Engineering Contradiction:
Improveprevention of liquefactionVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The control device converts the harmful compressive heat generated during gas transfer into a beneficial effect by utilizing it to maintain temperatures that prevent liquefaction. This reduces or eliminates the need for external heating, lowering energy consumption while maintaining reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach increases the probability of reactivating vacuum pumps, reduces maintenance and replacement frequencies, and minimizes manufacturing downtime by effectively managing the accumulation of solidified or liquefied products, thereby lowering maintenance costs and improving process reliability.

Implementation Method 1

the above-described vacuum pump generates compressive heat during the process of transferring gas, so that the vacuum pump in operation is at a high temperature to some extent

Methodology Applied
Scientific EffectCompression heat: Compression

Data Source

PatentEP3578825B1Control device, control system, control method, program and machine learning device
Publication Date: 2021.12.15 EBARA CORP
  • EP3578825B1 patent drawingFigure 1
  • EP3578825B1 patent drawingFigure 2
  • EP3578825B1 patent drawingFigure 3

AI summary

A control device (4) that controls a target vacuum pump (3) including a motor (31), including: a decision unit (452) that decides, using at least one of target state quantities at a time of a past stop process of the target vacuum pump or another vacuum pump wherein the target state quantities are state quantities which fluctuate in accordance with a load at a time of a process of stopping a vacuum pump, a normal fluctuation range or a normal time fluctuation behavior of the target state quantity at the time of the stop process; and a control unit (451) that controls the motor, wherein the control unit compares the target state quantity at the time of the process of stopping the target vacuum pump with the normal fluctuation range or the normal time fluctuation behavior, and changes a method of controlling the motor during the stop process depending on the comparison result.