Multi-Component Polymer Receiving Layer for Wafer Splitting

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Solution Overview

Problem

Current wafer production methods result in significant material losses and thickness fluctuations, leading to inefficient and costly solar cell production, with existing techniques failing to achieve uniform thickness and stable splitting of wafers.

Innovation Solution

A procedure involving a polymer coating with high thermal conductivity and strategically placed holes or chips to accelerate cooling, combined with thermal loading and a stop layer to induce precise cracking and splitting, allowing for uniform thickness and reduced material waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If a polymer layer is applied to the workpiece to create thermal tensions for splitting, then wafer production without Kerf-Loss is achieved, but the wafer bends severely towards the polymer layer making controlled splitting difficult and causing thick fluctuations

Engineering Contradiction:
Improvematerial lossVSAvoidthickness uniformity
Core Design Contradiction:
Loss of substanceVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating holes or recesses at specific locations in the polymer layer to locally reduce polymer thickness and bending influence. This allows different regions of the polymer layer to have different properties - areas with holes provide less bending force while maintaining thermal tension generation capability, thereby controlling wafer curvature and thickness uniformity during splitting.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining polymer material with regions of reduced polymer thickness (holes or recesses) to create a heterogeneous structure. This composite approach allows the polymer layer to simultaneously generate thermal tensions for splitting while reducing excessive bending through localized thickness variations, resolving the contradiction between material loss reduction and thickness precision.

Inventive Principle:
Principle #40Composite materials

2Force

If cooling is applied to the polymer layer to generate thermal tensions, then splitting can be achieved, but the process takes a very long time significantly affecting TTV

Engineering Contradiction:
Improvethermal tensionVSAvoidcooling time
Core Design Contradiction:
ForceVSLoss of time

Solution Approach 1:

The patent applies segmentation by introducing holes or recesses that divide the polymer layer into separate regions. This segmentation increases the surface area to volume ratio and creates thermal pathways that accelerate heat extraction during cooling, thereby reducing the time required to generate sufficient thermal tensions for splitting while maintaining control over TTV.

Inventive Principle:
Principle #1Segmentation

3Productivity

If the polymer layer is used to induce tensions for wafer splitting, then Kerf-Free Wafering is achieved, but severe curvature makes it difficult to continue processing and can lead to breaking the wafer

Engineering Contradiction:
Improvewafer production efficiencyVSAvoidwafer stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent uses local quality by creating holes or recesses at specific locations in the polymer layer to locally reduce bending forces. This allows the polymer layer to maintain its function of inducing thermal tensions for splitting while reducing excessive curvature in critical areas, thereby improving wafer stability and reliability during subsequent processing steps.

Inventive Principle:
Principle #3Local quality

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 method achieves wafers with a total thickness variation (TTV) of less than 120 micrometers, reducing material loss and improving processing stability, making the production more efficient and cost-effective.

Implementation Method 1

a polymer material, especially from PDMS, with a glass transition at a temperature of less than 0 °C

Methodology Applied
Scientific EffectGlass transition:

Implementation Method 2

A procedure involving a polymer coating with high thermal conductivity and strategically placed holes or chips to accelerate cooling

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3201944B1Combined wafer production method with a multi-component receiving layer
Publication Date: 2022.12.21 SILTECTRA GMBH
  • EP3201944B1 patent drawingFigure 1a~1c
  • EP3201944B1 patent drawingFigure 2a~2e

AI summary

The present invention relates to a method for producing solid body layers. The claimed method comprises at least the following steps: providing a solid body (2) for separating at least one solid body layer (4), arranging a receiving layer (10) on the solid body for holding the solid body layer (4), said receiving layer being made of at least one polymer and an additional material, said receiving layer, in terms of volume, be made mainly of polymer, the additional material having a greater conductivity than the polymer, and the receiving layer (10) is subjected to thermal stress, in particular, mechanical stress, for generating voltages in the solid body (2), wherein a crack in the solid body (2) along a separation plane (8) expands due to the voltages, the solid layer (4) being separated from the solid body (2) due to the crack.