Brittle Substrate Trench Line Division Control

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Solution Overview

Problem

Brittle substrates, such as glass, are prone to unintentional division during transportation or storage after forming a scribe line, as vertical cracks can penetrate further in the thickness direction, and there is a need to define the division position accurately before the intended breaking step.

Innovation Solution

A method involving forming a trench line on the substrate without a crack, which serves as a defined position for division, and subsequently extending a crack along this trench line to trigger the actual division, ensuring the substrate is not divided unintentionally before the intended time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a scribe line is formed on the substrate and then the substrate is transported or stored before the breaking step, then the substrate can be processed in between, but the substrate may be divided unintentionally during transportation or storage

Engineering Contradiction:
Improveability to process substrate between scribe line formation and breakingVSAvoidrisk of unintentional division during transportation or storage
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The method forms a trench line that defines the future division position in advance, but deliberately delays crack formation until the breaking step. This preliminary definition of the division position without immediate crack creation allows intermediate processing while preventing unintentional division during transportation or storage.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If the breaking step is performed immediately after forming a scribe line, then the division position is accurately defined, but the substrate cannot be processed in between and may require immediate transportation or storage

Engineering Contradiction:
Improveaccuracy of division positionVSAvoidflexibility in scheduling intermediate processing steps
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The trench line is formed as a preliminary structure that precisely defines the division position, but the actual crack formation is delayed. This allows intermediate processing steps to be scheduled flexibly between trench line formation and the breaking step, improving productivity while maintaining manufacturing precision through the pre-defined trench line position.

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If a vertical crack is formed during processing of the brittle substrate, then the division position is established, but the crack may penetrate further in the thickness direction unintentionally and separate the substrate

Engineering Contradiction:
Improvecontrol over division positionVSAvoidintegrity of substrate during processing
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The division process is segmented into two distinct stages: first forming a trench line that defines the division position without creating a through-crack, and then separately forming the vertical crack during the breaking step. This segmentation allows precise position control through the trench line while maintaining substrate integrity during intermediate processing, as the crack is only formed when intentionally triggered.

Inventive Principle:
Principle #1Segmentation

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 prevents unintentional division of brittle substrates during transportation or processing by maintaining a crack-free state until the defined trench line is used to form a crack line, allowing precise control over the division process.

Implementation Method 1

The cutter slides or rolls on the substrate, thus forming a trench on the substrate through a plastic deformation

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Implementation Method 2

Subsequently, a stress is applied to the substrate in a step referred to as a breaking step. The crack fully penetrates in the thickness direction in the breaking step, so that the substrate is divided.

Methodology Applied
Scientific EffectFracture mechanics: Fracture Mechanics

Data Source

PatentEP3150561B1Method for splitting brittle substrate
Publication Date: 2022.07.06 MITSUBOSHI DIAMOND IND CO LTD
  • EP3150561B1 patent drawingFigure 1(A)~1(E)
  • EP3150561B1 patent drawingFigure 2(A)~2(E)
  • EP3150561B1 patent drawingFigure 3(A)~3(B)

AI summary

A cutter edge (51) is caused to slide to generate a plastic deformation on a first surface (SF1) of a brittle substrate (4), thus forming a trench line (TL). The trench line (TL) is formed so as to obtain a crack-free state in which the brittle substrate (4) seamlessly continues in a direction intersecting the trench line (TL) directly below the trench line (TL). The crack-free state is then maintained. A crack of the brittle substrate (4) in its thickness direction is extended along the trench line (TL) to form a crack line (CL). The brittle substrate (4) is divided along the crack line (CL).