Laser Defect Wafer Separation Orthogonal Planes
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Solution Overview
Problem
Current methods for producing solid state elements, such as wafers for microelectronics and photovoltaics, result in significant material loss and thickness variations due to kerf loss and uncontrollable stress-induced cleavage, leading to unsuitable wafers for many applications.
Innovation Solution
A method involving the generation of defects in orthogonal planes using a laser to define detachment planes, with a polymer layer undergoing thermal stress to induce mechanical stresses for controlled crack propagation, allowing for precise separation of solid elements with minimal material loss and uniform thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If conventional sawing is used to produce wafers from an ingot, then material can be separated into wafers, but significant material loss occurs as kerf loss
Solution Approach 1:
The patent extracts and removes a thin wafer layer from a thicker workpiece using temperature-induced stresses and laser-generated defects, eliminating the need for conventional sawing and the associated kerf loss. The wafer is separated by inducing cracks along predetermined planes rather than mechanically cutting through the material.
Solution Approach 2:
The patent replaces the mechanical sawing system with a thermal-stress-based separation system. Laser radiation creates localized defects, and subsequent temperature changes induce stresses that propagate cracks along desired detachment planes, substituting mechanical cutting with a combination of optical and thermal mechanisms.
2Loss of substance
If temperature-induced stresses are used to separate wafers without sawing, then material loss is reduced, but the wafers exhibit strong curvature and thickness variations
Solution Approach 1:
The patent applies preliminary laser treatment to generate specific defect patterns in the workpiece before applying temperature-induced stresses. These pre-created defects serve as controlled initiation points for crack propagation, ensuring that cracks follow predetermined paths and resulting in uniform wafer thickness without the curvature problems of conventional methods.
Solution Approach 2:
The patent creates localized defects at specific positions and depths within the workpiece using focused laser radiation. This local modification of material structure allows precise control over where cracks will initiate and propagate, enabling uniform stress distribution and consistent wafer thickness across the entire wafer surface.
3Manufacturing precision
If laser radiation is used to generate defects for detachment planes, then controlled crack propagation is achieved, but energy consumption increases
Solution Approach 1:
The patent applies laser radiation selectively only at the locations where defects are needed to initiate crack propagation, rather than treating the entire workpiece. This partial action approach minimizes energy consumption while achieving the necessary control over crack paths for precise wafer separation.
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 method enables the production of solid state elements with reduced material loss and uniform thickness, improving the quality and cost-effectiveness of wafer production by defining predetermined breaking points and controlling crack propagation for consistent thickness across the wafer.
Implementation Method 1
creating a first group of defects by means of a laser to specify a first detachment plane along which the solid layer is separated from the solid body
Implementation Method 2
a polymer layer applied to the workpiece is used to generate these stresses
Implementation Method 3
by utilizing a glass transition, a relatively high modulus of elasticity can be achieved in the polymer layer, so that sufficiently large stresses can be induced in the polymer layer-workpiece layer system by cooling
Data Source
Figure 1a~1c
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to a method for manufacturing solid-state elements, in particular carrier elements for receiving electrically conductive components. The method comprises at least the following steps: providing a solid body for separating at least one solid-state layer, generating a first group of defects using a laser (18) to define a first detachment plane along which the solid-state layer is separated from the solid body, generating a second group of defects using the laser to define at least a second detachment plane (50), wherein the first detachment plane and the second detachment plane are orthogonally aligned to each other, detaching the solid-state layer from the solid body along the first detachment plane as a result of generating stresses in the solid body, and parting the solid-state layer along the second detachment plane (50) to separate the solid-state elements.