Piston Pump Controller Dispensing Accuracy

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Solution Overview

Problem

Conventional substrate treating apparatuses struggle to accurately adjust the dispensed amount of resist solution due to varying dispensed amounts per predetermined drive pulse, limiting precision in dispensing time and speed corrections.

Innovation Solution

A pumping apparatus with a controller that determines an imaginary terminal point by referencing a dispense command, theoretical information, and correction information to adjust the position of a movable member within the pump chamber, ensuring accurate dispensing of a target amount of liquid by correcting the imaginary terminal point to a target position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the controller corrects dispensing time or dispensing speed based on a single correction value, then the control process is simple, but the dispensed amount cannot be adjusted appropriately when the dispensed amount per drive pulse varies

Engineering Contradiction:

Improvecontrol process simplicityVSAvoiddispensed amount accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent divides the correction process into two distinct segments: (1) correction of the terminal point position based on cumulative dispensed amount differences, and (2) correction of drive pulse parameters (time/speed) based on per-pulse dispensed amount variations. This segmentation allows each correction to address specific sources of error independently, resolving the contradiction between simple control and accurate dispensing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The controller performs preliminary correction of the terminal point position before executing the dispensing operation. By calculating the cumulative dispensed amount difference in advance and adjusting the terminal point accordingly, the system prepares for accurate dispensing before the actual process begins, ensuring both simplicity and precision.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If the controller uses a single correction value for all drive pulses, then the correction process is straightforward, but accuracy deteriorates when dispensed amount varies with pulse number

Engineering Contradiction:

Improvecorrection process complexityVSAvoiddispensed amount measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements dynamic correction by adjusting the terminal point position based on cumulative dispensed amount differences that vary with the number of drive pulses. Instead of using a static correction value, the system dynamically adapts the terminal point position according to the actual dispensed amount characteristics, maintaining high accuracy while managing complexity through systematic calculation.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms by measuring the actual dispensed amount per drive pulse and using this information to correct the terminal point position. The controller continuously monitors and adjusts based on the difference between theoretical and actual dispensed amounts, ensuring measurement precision while maintaining reasonable process complexity.

Inventive Principle:

Principle #23Feedback

3Device complexity

If the controller adjusts dispensing parameters based on theoretical relationships only, then the control logic is simple, but the actual dispensed amount deviates from the target value

Engineering Contradiction:

Improvecontrol logic simplicityVSAvoiddispensed amount precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements feedback by measuring the actual dispensed amount per drive pulse and comparing it with the theoretical dispensed amount. The controller uses the difference (correction value) to adjust the terminal point position, ensuring that the actual dispensed amount matches the target value. This feedback mechanism resolves the contradiction by maintaining control logic simplicity while achieving high dispensing precision.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces purely theoretical mechanical control with a corrected control system that incorporates actual measurement data. By substituting theoretical terminal point positions with corrected positions based on actual dispensed amount measurements, the system achieves higher precision while maintaining logical simplicity through systematic correction calculations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 allows for high-accuracy adjustment of the dispensed liquid amount, improving the precision and consistency of the dispensing process, thereby enhancing the quality of substrate treatment.

Implementation Method 1

the pump chamber being configured to dispense the liquid in the pump chamber outside the pump chamber by reduction of a volume in the pump chamber

Methodology Applied

Scientific EffectVolume reduction:

Data Source

PatentUS10627836B2Pumping apparatus and substrate treating apparatus

Publication Date: 2020.04.21 SCREEN HOLDINGS CO LTD

AI summary

A pumping apparatus includes a pump chamber, a piston, a motor, and a controller. The controller determines an imaginary terminal point by referring to a dispense command, theoretical information, and a current position of the piston. The controller corrects the imaginary terminal point to a target position by referring to a correction graph. The controller outputs a drive command to the motor for moving the piston from a start position to the target position.