Polysilicon Resin Analysis via Stepwise Thermal Decomposition

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Solution Overview

Problem

Conventional methods fail to accurately identify and quantify resins adhering to crushed polysilicon with high sensitivity and precision, particularly for trace quantities and resins with decomposition temperatures exceeding 350°C, such as fluororesin and PEEK, which are commonly used in the polysilicon production process.

Innovation Solution

A method involving the removal of organic volatile components from crushed polysilicon at 250°C or more but below the resin decomposition temperature, followed by stepwise heating in an inert gas atmosphere to collect and analyze resin decomposition products, allowing for precise identification and quantification of adhering resins by avoiding interference from volatile components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional heat treatment at 350-600°C is used to determine carbon quantity, then the whole quantity of adhering carbon can be measured, but the type of resin and the quantity of adhering resin cannot be specified

Engineering Contradiction:
Improvecarbon quantityVSAvoidresin type identification and quantity specification
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The heat treatment process is segmented into multiple temperature stages: a first heat treatment stage at a lower temperature (200-400°C) to remove volatile components, and a second heat treatment stage at a higher temperature (400-800°C) to decompose and analyze the resin. This segmentation allows both total carbon measurement and specific resin identification to be performed in sequence using the same apparatus.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first heat treatment at lower temperature is performed as a preliminary action to remove volatile components before the main resin decomposition analysis. This preliminary removal of interfering substances enables more accurate identification and quantification of the resin type in the subsequent higher temperature stage.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If heat treatment temperature is increased to analyze resins with decomposition temperatures exceeding 350°C, then detection sensitivity for trace resin components is improved, but volatile components interfere with the analysis

Engineering Contradiction:
Improvedetection sensitivity for trace resinVSAvoidinterference from volatile components
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

Volatile components are extracted and removed from the sample through a first heat treatment at lower temperature (200-400°C) before the main analysis. This extraction eliminates the harmful interference of volatile substances that would otherwise mask or interfere with the detection of trace resin decomposition products at higher temperatures.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The removal of volatile components through first heat treatment is performed as a preliminary action before the main resin decomposition analysis. This preliminary step creates a cleaner sample that allows for more sensitive and accurate detection of trace resin components in the subsequent higher temperature stage.

Inventive Principle:
Principle #10Preliminary action

3Loss of information

If conventional GC-MS analysis is used for resin identification, then qualitative analysis can be performed, but quantitative determination with high precision is not achieved

Engineering Contradiction:
Improveresin component identificationVSAvoidquantitative determination precision
Core Design Contradiction:
Loss of informationVSMeasurement precision

Solution Approach 1:

The conventional GC-MS analysis is replaced with a thermal decomposition-based analysis method that measures the volume of gas evolved during controlled heat treatment. This substitution provides more precise quantitative determination of resin content while still enabling identification of resin type through the characteristics of the decomposition products.

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 method enables precise identification and quantification of resins on crushed polysilicon surfaces, determining contamination sources and improving production processes by accurately detecting resin types and quantities, even in trace amounts and beyond the temperature limitations of previous methods.

Implementation Method 1

removal of organic volatile components from crushed polysilicon which is carried out while maintaining the temperature at 250°C or more and lower than the decomposition starting temperature

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

raising the temperature of the crushed polysilicon in a stream of an inert gas, wherein the rise of the temperature of the crushed polysilicon is carried out stepwise in a temperature range of not lower than the resin decomposition starting temperature, collecting resin decomposition products

Methodology Applied
Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentEP3557246B1Method of analyzing resins adhering to crushed polysilicon
Publication Date: 2023.04.26 TOKUYAMA CORP
  • EP3557246B1 patent drawingFigure 1
  • EP3557246B1 patent drawingFigure 2

AI summary

Provided is an analysis method capable of qualitatively determining resins adhering to crushed polysilicon with high sensitivity and further capable of quantitatively determining the resins with high precision. The analysis method comprises removing organic volatile components from crushed polysilicon by heating, then raising a temperature of the crushed polysilicon in a stream of an inert gas, collecting resin decomposition products produced at the heating temperature, and analyzing decomposition products unique to the resins, to thereby identify the types of the resins adhering to the crushed polysilicon. Moreover, it is also possible to prepare a standard curve regarding each of the decomposition products unique to the resins and to determine an adhesion quantity of each of the adhering resins based on the standard curve.