Polyurethane Mounting Pad Low Pressure Compressibility

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Solution Overview

Problem

Existing polyurethane mounting pads with high compressibility and compression recovery rates, as per JIS standards, fail to achieve uniform and precise polishing at low pressure conditions, leading to defective polishing during the processing of glass substrates for display devices.

Innovation Solution

A polyurethane mounting pad with Low P compressibility of 1 to 10% and Low P compression length of 15 to 100 µm, achieved through an immersion process in an aqueous solution and heat treatment, allowing for sufficient compression under practical polishing pressures and uniform force distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a mounting pad with high compressibility and compression recovery rate is used according to JIS standards, then the compressibility is improved, but the polishing uniformity and precision deteriorate under low pressure conditions

Engineering Contradiction:
ImprovecompressibilityVSAvoidpolishing uniformity
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent changes the measurement parameter from standard JIS compressibility (100g/cm²) to low-pressure compressibility (5g/cm²) to better reflect actual polishing conditions. It also introduces compression length as a new parameter to quantify the pad's deformation under practical loads, enabling optimization of polishing performance rather than just meeting standard specifications.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional mechanical compression test with a low-pressure immersion process that simulates actual polishing conditions. This substitution allows the pad to be evaluated and treated under the same mechanical conditions it will experience during polishing, revealing performance characteristics that standard high-pressure tests miss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Stability of the object's composition

If the mounting pad is treated through immersion process and heat treatment to improve compressibility, then the compression recovery rate is improved, but the process complexity increases

Engineering Contradiction:
Improvecompression recovery rateVSAvoidprocess complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies preliminary treatment steps (immersion in aqueous solution, heat treatment) before the actual polishing process. These pre-treatments prepare the mounting pad in advance to achieve optimal compressibility and compression recovery rate, ensuring that the pad is already in the desired state when polishing begins, rather than adjusting during the process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes phase transition through heat treatment to alter the physical properties of the mounting pad. By controlling temperature changes during the treatment process, the pad's molecular structure is reconfigured to achieve better compressibility and elastic recovery, leveraging thermal energy to transform the material's properties.

Inventive Principle:
Principle #36Phase transitions

3Stress or pressure

If the mounting pad compresses sufficiently under low pressure, then the force distribution is improved, but the compression length increases

Engineering Contradiction:
Improveforce distributionVSAvoidcompression length
Core Design Contradiction:
Stress or pressureVSLength of stationary object

Solution Approach 1:

The patent optimizes the compression length parameter by controlling the low-pressure treatment conditions. By carefully managing the immersion time, temperature, and pressure levels during the treatment process, the pad achieves the optimal balance where sufficient compression occurs for uniform force distribution without excessive compression length that would compromise structural integrity.

Inventive Principle:
Principle #35Parameter changes

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 solution enables more uniform and high-efficiency polishing, reducing the defective polishing rate by ensuring even force distribution and impact absorption during the polishing of glass substrates at low pressure conditions.

Implementation Method 1

a mounting pad having excellent compressibility and compression length under low pressure

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

excellent elastic power under practical polishing conditions

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2998345B1Polyurethane support pad
Publication Date: 2018.12.05 LG CHEM LTD
  • EP2998345B1 patent drawingFigure 1~2
  • EP2998345B1 patent drawingFigure 3~4
  • EP2998345B1 patent drawing

AI summary

This disclosure relates to a polyurethane mounting pad having Low P compressibility of 1 to 10%, the Low P compressibility being the ratio of the difference between a first thickness and a second thickness to the first thickness, the first thickness being measured by applying a pressure of 5g/cm2 to a thickness direction of the mounting pad, and the second thickness being measured by applying a pressure of 100g/cm2 to a thickness direction of the mounting pad, wherein Low P compression length, which is the difference between the first thickness and the second thickness, is 15 to 100 µm. According to the present invention, provided is a polyurethane mounting pad that has high compressibility and excellent elastic power under practical polishing conditions, and can realize more uniform and high efficiency polishing to decrease defective polishing rate.