Ingot Temperature Control in Wire Sawing to Prevent Wafer Cut Offset

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

During the wire sawing process for manufacturing silicon wafers, ingot shrinkage due to process heat fluctuations can lead to quality deterioration and offset cutting positions when errors occur in the wire sawing apparatus, resulting in suboptimal wafer production.

Innovation Solution

A wire sawing apparatus equipped with an ingot temperature controller that includes a temperature measurement unit and a heater unit, controlled by a unit to maintain uniform ingot temperature, ensuring consistent processing conditions even during facility shutdowns or errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the wire sawing process continues with high-speed rotation and friction, then productivity is improved, but temperature increases causing ingot shrinkage and quality deterioration

Engineering Contradiction:

Improvewafer production efficiencyVSAvoidingot temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent converts the harmful friction heat that causes ingot shrinkage into a beneficial controlled heating process. By introducing a heater unit and temperature control system, the previously harmful temperature rise is transformed into a controlled thermal environment that prevents shrinkage while maintaining cutting efficiency.

Inventive Principle:

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

Solution Approach 2:

The patent changes the thermal parameter control by adding active heating capability. Instead of merely managing heat dissipation, the system now actively controls temperature through a heater unit, allowing the ingot temperature to be maintained at optimal levels despite the high-speed cutting operations.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If the wire sawing apparatus operates continuously, then productivity is improved, but errors cause temperature fluctuations leading to cutting position offset and quality deterioration

Engineering Contradiction:

Improvecontinuous wafer productionVSAvoidcutting position accuracy

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent implements a feedback control system where temperature is continuously monitored and the heater unit adjusts accordingly. This feedback mechanism ensures that even when errors occur during continuous operation, the temperature remains stable, preventing the cutting position offset that would otherwise occur during resumption.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent prepares for potential errors by maintaining a controlled thermal environment throughout continuous operation. The heater unit acts as a cushioning mechanism that prevents temperature drops during interruptions, ensuring that when the wire sawing resumes, the ingot is already at the correct temperature, preventing cutting position offset.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Use of energy by moving object

If the ingot is allowed to cool during errors, then energy consumption is reduced, but the ingot shrinks causing quality deterioration and rework

Engineering Contradiction:

Improveenergy consumption during errorsVSAvoidwafer cutting quality

Core Design Contradiction:

Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent converts the previously harmful continuous heating requirement into a beneficial controlled heating system. By adding the heater unit with temperature control, the system can now maintain quality during errors with minimal energy consumption, as heating is only applied when temperature drops occur rather than continuous heating.

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

The solution effectively prevents quality deterioration by maintaining uniform ingot temperature, thereby improving the quality and consistency of wafer production by minimizing shrinkage-related issues.

Implementation Method 1

a temperature measurement unit mounted in the chamber in which the ingot is cut, the temperature measurement unit being configured to measure the temperature of the ingot

Methodology Applied

Scientific EffectTemperature measurement:

Implementation Method 2

a heater unit mounted in the chamber... When the temperature measured by the temperature measurement unit is equal to or less than a set temperature, the control unit may operate the heater unit

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

the ingot is cut into a plurality of wafers due to friction between the ingot and the slurry attached to the wire. During the slicing process, the ingot swells in the chamber while the temperature of the ingot is being increased by process heat generated due to rotation of the rollers and the wire and friction between the wire and the ingot

Methodology Applied

Scientific EffectFriction heat: Friction

Data Source

PatentUS12090685B2Ingot temperature controller and wire sawing device having same

Publication Date: 2024.09.17 SK SILTRON CO LTD

AI summary

Provided is a wire sawing device comprising an ingot temperature controller, the wire sawing device comprising: a chamber; an ingot clamp supporting an ingot inside the chamber; a first roller and a second roller; a wire which is wound around the first roller and the second roller and cuts the ingot into a plurality of wafers by rotating; a temperature measuring unit which is mounted inside the chamber, in which the ingot is cut, and measures the temperature of the ingot; and a heater unit mounted inside the chamber.