Laser Peel-Off Layer Formation for Low-Waste Substrate Separation

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Solution Overview

Problem

The existing method of manufacturing substrates from workpieces using a wire saw results in significant material wastage, reducing productivity due to the discarding of 60% to 70% of the workpiece as debris, which is inefficient for producing thinner substrates.

Innovation Solution

A laser-based method is employed to form a peel-off layer inside the workpiece by alternating the movement of the workpiece and focusing points of laser beams with varying output powers, forming first and second modified portions to control crack development and facilitate separation, thereby manufacturing a thinner substrate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wire saw is used to manufacture substrate from workpiece, then substrate can be manufactured, but 60% to 70% of workpiece is discarded as debris causing reduction of productivity

Engineering Contradiction:

Improvesubstrate manufacturing productivityVSAvoidworkpiece material waste

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical wire saw cutting method with a laser-based method to form a peel-off layer inside the workpiece. The laser beam forms modified portions that create controlled internal stress, enabling the workpiece to be separated into substrate and debris through peeling action rather than mechanical cutting, thereby reducing material waste and improving productivity

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the workpiece material by applying laser energy to create modified portions with different thermal and mechanical properties. The alternating high and low output power laser beams create distinct first and second modified portions with different internal stresses, enabling controlled crack development and peeling separation

Inventive Principle:

Principle #35Parameter changes

2Loss of substance

If laser beam is applied to form peel-off layer, then material waste is reduced, but process complexity increases due to alternating movement of workpiece and focusing points

Engineering Contradiction:

Improveworkpiece material wasteVSAvoidlaser processing system complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent segments the laser beam output into alternating high and low power portions, creating first modified portions and second modified portions with different properties. The workpiece and focusing points are also segmented into discrete movement steps, allowing precise control of the peel-off layer formation while managing system complexity through structured segmentation

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs periodic alternating action by repeatedly switching between high output power and low output power laser beams, and between moving the workpiece and moving the focusing points. This periodic pattern creates the alternating first and second modified portions that enable controlled crack development and efficient peeling separation

Inventive Principle:

Principle #19Periodic 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

This approach enhances the productivity of substrate manufacturing by minimizing material waste and improving the efficiency of substrate production compared to traditional wire saw methods.

Implementation Method 1

applying, to the workpiece, a laser beam of a wavelength transmittable through a material of the workpiece, thereby forming a peel-off layer inside the workpiece

Methodology Applied

Scientific EffectLaser heating: Laser

Implementation Method 2

the peel-off layer including first modified portions and second modified portions which are alternately lined up in the second direction is formed, the first modified portion is formed at a first focusing point at which a first laser beam having first output power is focused, and the second modified portion is formed at a second focusing point at which a second laser beam having a second output power greater than the first output power is focused

Methodology Applied

Scientific EffectThermal stress: Thermal Expansion

Data Source

PatentUS20250256358A1Substrate manufacturing method

Publication Date: 2025.08.14 DISCO CORP

AI summary

A substrate manufacturing method includes applying a laser beam of a wavelength transmittable through a material of a workpiece, thereby forming a peel-off layer inside the workpiece, and after the forming of the peel-off layer, with the peel-off layer as a starting point of separation, separating the workpiece, thereby manufacturing a substrate. In the forming of the peel-off layer, by alternately repeating moving the workpiece and a focusing point at which the laser beam is focused relative to each other along a first direction, in a state in which the focusing point is positioned inside the workpiece, and moving the workpiece and a position at which the focusing point is formed relative to each other along a second direction perpendicular to the first direction, the peel-off layer including first modified portions and second modified portions which are alternately lined up in the second direction is formed.