Multi-Laser Sintering for OLED Glass Cement Crack Prevention
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Solution Overview
Problem
Conventional laser sintering processes for OLED display devices result in cracks and breakages due to accumulated shrinkage stress in glass cement, as it is heated and cooled rapidly, and existing methods to mitigate this either restrict material choices or are not suitable for mass production.
Innovation Solution
A laser sintering apparatus and method using multiple laser heads with different power levels and controlled movement to preheat, sinter, and anneal the glass cement, reducing temperature differences and cooling rates, thereby minimizing stress on the glass cement and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If laser sintering speed is increased to improve productivity, then manufacturing efficiency is improved, but shrinkage stress accumulates causing cracks and breakages in glass cement
Solution Approach 1:
The patent divides the single laser sintering process into three distinct stages using three laser heads: preheating stage (first laser head at lower power), rapid heating stage (second laser head at high power), and cooling stage (third laser head at lower power). This segmentation allows each stage to be optimized independently, enabling high overall productivity while preventing crack formation through controlled temperature transitions.
Solution Approach 2:
The first laser head performs preheating of the glass cement before the main sintering process. This preliminary action gradually raises the temperature of the glass cement and substrate, reducing the thermal shock and preventing sudden stress accumulation that would occur with direct high-power heating, thereby maintaining glass cement integrity during high-speed processing.
2Productivity
If laser power is increased to reduce processing time, then productivity is improved, but thermal stress causes cracks and breakages
Solution Approach 1:
The patent applies different power levels to different spatial and temporal regions of the glass cement. The first laser head applies low power for preheating, the second laser head applies high power for rapid sintering, and the third laser head applies low power for controlled cooling. This local quality approach ensures that each region of the glass cement experiences appropriate heating rates, preventing thermal stress-induced cracks while maintaining high overall processing efficiency.
3Productivity
If cooling rate is increased to improve cycle time, then productivity is improved, but shrinkage stress causes cracks and breakages
Solution Approach 1:
The patent implements a periodic action pattern with three distinct phases: preheating phase, rapid heating phase, and controlled cooling phase. Each phase is executed in sequence with the third laser head following the second laser head, creating a rhythmic thermal cycle that allows the glass cement to cool at an optimized rate. This periodic thermal action reduces shrinkage stress accumulation while maintaining efficient cycle times for mass production.
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 approach effectively reduces the occurrence of cracks and breakages by gradually heating and cooling the glass cement, improving the packaging process and maintaining material flexibility, making it applicable to mass production.
Implementation Method 1
heat and melt, in a precise and quick manner, a glass cement at a specific position between two glass substrates (one is a cover plate, while the other is a back plate on which the light-emitting material and a circuit pattern are formed) by using a laser beam
Implementation Method 2
The first laser head, the second laser head and the third laser head are used to heat the glass cement successively
Implementation Method 3
A shrinkage stress may be accumulated inside the glass cement during the quick heating and cooling
Data Source
AI summary
The present disclosure provides a laser sintering apparatus and a laser sintering method. The laser sintering apparatus includes a first laser head configured to output a laser beam at a first power level, a second laser head configured to output a laser beam at a second power level, and a driving device configured to drive the first laser head and the second laser head to move, so as to enable the first laser head and the second laser head to heat an identical region of a to-be-sintered material.