Asymmetric Polymer Substrate for Flexible Display Stress Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Flexible liquid crystal display devices face issues with foreign matter contamination and uneven substrate thickness, leading to poor display performance due to broken metal lines and excessive resistance, as well as asymmetrical stresses causing damage to thin-film transistor layers.
Innovation Solution
The use of a first polymer substrate with a greater thickness than a second polymer substrate, with thin-film transistors disposed on the first substrate and a liquid crystal layer in between, to mitigate protrusion elements and adjust the neutral plane, reducing stress and improving flatness and display quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If both plastic substrates are thinned to achieve lightness and thinness, then weight and thickness are reduced, but asymmetrical stresses are generated causing electrodes and metal lines to break
Solution Approach 1:
The patent applies asymmetry by making the first plastic substrate thicker than the second plastic substrate. This asymmetric thickness configuration balances the stress distribution in the display device, preventing asymmetrical stresses that would otherwise cause electrodes and metal lines to break during bending, while still maintaining overall thinness and lightness.
2Length of stationary object
If substrate thickness is reduced to achieve thinness, then overall device thickness is reduced, but surface uplift occurs due to foreign matter and solute precipitation
Solution Approach 1:
The patent applies local quality by creating a protrusion portion on the first plastic substrate at the location where foreign matter or solute precipitation occurs. This localized thickness increase compensates for surface uplift without requiring the entire substrate to be thicker, thus maintaining overall thinness while improving surface flatness for metal trace formation.
3Manufacturing precision
If substrate thickness is increased to improve flatness and reduce stress, then overall device thickness increases, but the lightness advantage is reduced
Solution Approach 1:
The patent applies local quality by creating a protrusion portion only at the specific location where foreign matter or solute precipitation occurs, rather than uniformly increasing the thickness of the entire first plastic substrate. This localized approach improves surface flatness and stress distribution while minimizing the overall thickness increase, preserving the lightness advantage.
Data Source
AI summary
A display device is provided and includes a first polymer substrate, a plurality of thin-film transistors, a second polymer substrate, and a liquid crystal layer. The thin-film transistors are disposed on the first polymer substrate. The second polymer substrate is disposed opposite to the first polymer substrate. The liquid crystal layer is disposed between the first polymer substrate and the second polymer substrate. The first polymer substrate has a first thickness, the second polymer substrate has a second thickness, and the first thickness is greater than the second thickness.