Laser-Created Detachment Zones for Low-Waste Solid Layer Separation

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Solution Overview

Problem

Conventional methods for separating solid portions, such as wafers, using sawing result in material waste, surface damage, and high costs due to the production of chips and thickness fluctuations, while laser-based methods face challenges with thermal stress and precision in crystal lattice modification.

Innovation Solution

A method utilizing LASER radiation to induce controlled material transformations or phase changes in solids, allowing for precise weakening and separation of solid layers without local destruction of the crystal lattice, using specific materials like silicon carbide and ceramics, with controlled temperature and pulse density, and a cooling device to manage thermal stress.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If sawing is used to separate solid portions, then separation can be achieved, but material waste increases due to chip production

Engineering Contradiction:
Improveseparation capabilityVSAvoidmaterial waste
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The patent replaces the mechanical sawing system with a laser-based system that uses optical energy to induce material transformation. The laser modifies the crystal structure through controlled heating and cooling cycles, creating detachment regions without mechanical contact, thereby eliminating chip production and material waste.

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

Solution Approach 2:

The patent utilizes controlled changes in temperature parameters during laser exposure to induce phase transformations in the crystal structure. By cycling between heating (melting) and cooling (solidification) phases, the material properties are temporarily altered to create weak detachment regions that separate cleanly without material loss.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If sawing is used to separate solid portions, then separation can be achieved, but surface damage occurs due to grooves and surface defects

Engineering Contradiction:
Improveseparation capabilityVSAvoidsurface damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces mechanical sawing with a non-contact laser process that modifies material properties through thermal energy. This eliminates mechanical grooves and surface defects caused by saw blades, producing clean separation surfaces without physical contact damage.

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

Solution Approach 2:

The patent employs controlled phase transitions (melting and solidification) of the crystal structure during laser exposure. The material melts and then solidifies to form a modified detachment region that separates cleanly, leaving smooth surfaces without the grooves and defects characteristic of mechanical sawing.

Inventive Principle:
Principle #36Phase transitions

3Manufacturing precision

If laser radiation is used to modify crystal structure, then precise separation can be achieved, but thermal stress and distortion occur

Engineering Contradiction:
Improveseparation precisionVSAvoidthermal stress
Core Design Contradiction:
Manufacturing precisionVSStress or pressure

Solution Approach 1:

The patent employs periodic laser exposure with controlled heating and cooling cycles. The laser is applied in a rhythmic manner, heating the material to induce phase transformation and then allowing controlled cooling. This periodic action enables precise separation while managing thermal stress through repeated thermal cycles rather than continuous heating.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent utilizes controlled phase transitions between solid, liquid, and solid states during laser exposure. The material is heated to melt and then cooled to solidify, forming a modified detachment region. These phase transitions enable precise separation by creating a distinct boundary zone while the controlled cycling manages thermal stress accumulation.

Inventive Principle:
Principle #36Phase transitions

4Manufacturing precision

If high temperatures are applied for laser separation, then material transformation can be achieved, but solid distortion and expansion occur

Engineering Contradiction:
Improvematerial transformationVSAvoidsolid distortion
Core Design Contradiction:
Manufacturing precisionVSShape

Solution Approach 1:

The patent employs periodic laser exposure with controlled heating and cooling cycles. High temperatures are applied temporarily to induce phase transformation, followed by controlled cooling periods that allow the material to return to its original shape. This rhythmic heating and cooling enables material transformation while minimizing permanent distortion and expansion.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent utilizes controlled phase transitions where the material is heated to melt and then cooled to solidify in a controlled manner. These reversible phase changes enable precise material transformation and separation while the controlled cooling process minimizes thermal distortion and expansion, maintaining the solid's overall shape integrity.

Inventive Principle:
Principle #36Phase transitions

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

Enables precise and controlled separation of solid layers with reduced material loss and thermal stress, improving processing efficiency and reducing material costs by minimizing chip production and surface damage.

Implementation Method 1

a predetermined portion (9) of the solid body (1) is heated using a laser beam (4) to a temperature at which a material transformation or phase transformation of the heated portion (9) occurs

Methodology Applied
Scientific EffectLaser heating: Laser

Implementation Method 2

The at least one laser beam (4) heats the predetermined portion (9) of the solid body (1) to a temperature that is so high that a predetermined material transformation takes place in the predetermined portion (9) forming the detachment area (2)

Methodology Applied
Scientific EffectThermal heating: Heating

Implementation Method 3

with controlled temperature and pulse density, and a cooling device to manage thermal stress

Methodology Applied
Scientific EffectThermal cooling: Cooling

Data Source

PatentEP3253529B1Separation of a solid body by material modification
Publication Date: 2023.04.26 SILTECTRA GMBH
  • EP3253529B1 patent drawingFigure 1
  • EP3253529B1 patent drawingFigure 2
  • EP3253529B1 patent drawingFigure 3

AI summary

The invention relates to a method for creating a detachment zone (2) in a solid (1) in order to detach a solid portion (12), especially a solid layer (12), from the solid (1), said solid portion (12) that is to be detached being thinner than the solid from which the solid portion (12) has been removed. The method according to the invention preferably comprises at least the steps of: providing a solid (1) which is to be processed and which is made of a chemical compound; providing a LASER light source; and subjecting the solid (1) to LASER radiation from the LASER light source so that the laser beams penetrate into the solid (1) via a surface (5) of the solid portion (12) that is to be cut off; the LASER radiation controlling the temperature of a predefined portion of the solid (1) inside the solid (1) in a defined manner such that a detachment zone (2) or a plurality of partial detachment zones (25, 27, 28, 29) is formed; characterized in that the temperature produced by the laser beams in a predefined portion of the solid (1) is so high that the material forming the predefined portion is subject to modifications (9) in the form of a predetermined conversion of material.