Thinner Composition for LCD Nozzle Cleaning and Recovery

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Solution Overview

Problem

Conventional thinner compositions struggle to effectively clean and maintain the cleanliness of photoresist spray nozzles used in linear coating methods for LCD manufacturing, leading to contamination and defects in subsequent processing steps, and most thinner compositions are treated as waste, increasing manufacturing costs.

Innovation Solution

A thinner composition comprising 60-80% propylene glycol mono-alkyl ether, 10-30% alkyl acetate, and 1-10% solvent with specific boiling point relationships is used to clean and recover the nozzle, allowing for efficient fractional distillation and recycling of the composition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional thinner compositions are used to clean photoresist spray nozzles, then the nozzles become contaminated and cleaning effectiveness decreases, but using specialized thinner compositions increases manufacturing costs

Engineering Contradiction:

Improvenozzle cleanlinessVSAvoidmanufacturing cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements a recovery system that collects used thinner from the cleaning process and regenerates it through filtration and distillation. The recovered thinner is then reused in the cleaning process, creating a closed-loop system that reduces both waste disposal costs and the need for continuous purchase of fresh thinner, thereby addressing the cost concern while maintaining cleaning effectiveness

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The patent develops a specialized thinner composition with specific chemical properties optimized for removing photoresist from nozzles. This composite thinner formulation provides superior cleaning performance compared to conventional thinners, ensuring nozzle cleanliness and preventing contamination that would otherwise require more expensive maintenance or replacement

Inventive Principle:

Principle #40Composite materials

2Manufacturing precision

If linear coating method is used to coat photoresist uniformly, then coating precision improves, but nozzle contamination occurs leading to defects in subsequent processing

Engineering Contradiction:

Improvephotoresist coating uniformityVSAvoidnozzle contamination

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent implements a cleaning mechanism that operates continuously during the linear coating process. The thinner is supplied to the nozzle at controlled intervals to prevent photoresist accumulation, and the cleaning action is synchronized with the coating operation to maintain nozzle cleanliness throughout the process, preventing contamination before it can cause defects

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent establishes a continuous cleaning system where thinner is constantly supplied to the nozzle during the linear coating process. This continuous action ensures that photoresist is removed as it accumulates, maintaining consistent nozzle performance throughout the coating operation and preventing the contamination that would otherwise occur with intermittent cleaning

Inventive Principle:

Principle #20Continuity of useful action

3Reliability

If more thinner is used for cleaning, then cleaning effectiveness improves, but waste generation and recovery complexity increase

Engineering Contradiction:

Improvecleaning effectivenessVSAvoidrecovery system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies a controlled amount of thinner to the nozzle surface - sufficient to dissolve and remove photoresist contamination but not so much as to create excessive waste. The thinner is applied in a targeted manner directly to the nozzle interior, ensuring adequate cleaning effectiveness while minimizing the volume of waste that requires recovery processing

Inventive Principle:

Principle #16Partial or excessive action

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

The composition effectively cleans the nozzle, maintaining its cleanliness and enabling uniform photoresist coating, while also allowing for high recovery and recycling of the thinner, reducing waste and manufacturing costs.

Implementation Method 1

a thinner composition for cleaning/washing an object (e.g. spray nozzle of a linear coating machine) having a photoresist disposed therewith

Methodology Applied

Scientific EffectSolvation: Solvation

Implementation Method 2

a method of recovering the same wherein the waste thinner composition is fractionally distilled

Methodology Applied

Scientific EffectFractional distillation: Distillation

Data Source

PatentUS7612028B2Thinner composition, method of preparing the same and method of recovering the same

Publication Date: 2009.11.03 SAMSUNG DISPLAY CO LTD

AI summary

A thinner composition is provided which includes about 60-80% by weight of propylene glycol mono-alkyl ether having a boiling point of T1° C., about 10-30% by weight of alkyl acetate having a boiling point of T2° C., and about 1-10% by weight of a solvent. The solvent has a boiling point of T3° C. and satisfies the equation (1).T2<T3<T2+30 (1).