Bendable Substrate Insulating Layer Cracking Prevention
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Solution Overview
Problem
Existing electronic devices face issues with cracking when bent due to low ductility and poor bonding between light-emitting units and conductive pads, leading to reduced yield and performance.
Innovation Solution
Incorporating a bendable substrate with a ductile insulating layer and a substantially planar insulating layer between the light-emitting unit and the substrate, allowing conductive pads to be at the same level, which reduces cracking and improves bonding and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rigid substrate is used to maintain structural strength, then the device has high strength, but it cannot be bent and has poor flexibility
Solution Approach 1:
The substrate is divided into a bendable portion and a non-bendable portion, allowing different regions to have different mechanical properties. The non-bendable portion maintains structural strength while the bendable portion enables flexibility.
Solution Approach 2:
Different portions of the substrate are given different properties: the non-bendable portion provides structural support while the bendable portion allows flexibility. This local differentiation resolves the contradiction between overall strength and local flexibility.
2Length of moving object
If a thin insulating layer is used to reduce device thickness, then the device is thinner, but cracking occurs during bending
Solution Approach 1:
The insulating layer is made thicker specifically in the bendable portion where cracking risk is highest, while maintaining thin thickness in the non-bendable portion to keep the overall device thin. This local thickening prevents cracking without sacrificing device compactness.
Solution Approach 2:
The insulating layer is designed with increased thickness in advance in the bendable portion, providing a cushioning effect that prevents cracking before it occurs during bending operations.
3Strength
If conventional bonding methods are used between light-emitting units and conductive pads, then the process is simple, but bonding strength is insufficient
Solution Approach 1:
The conductive pads are positioned at the same level as the light-emitting units, creating a flush bonding surface. This eliminates height differences and facilitates stronger, more reliable bonding without requiring complex bonding processes.
Solution Approach 2:
The bonding surface is designed to be substantially planar, copying the flat geometry of the light-emitting units. This ensures uniform contact and maximizes bonding area, improving bonding strength through geometric optimization rather than process complexity.
Data Source
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AI summary
An electronic device is provided. The electronic device includes a substrate, a plurality of thin-film transistors disposed on the substrate, and a plurality of light-emitting units. One of the light-emitting units has an encapsulating glue and at least one light-emitting chip. The encapsulating glue is disposed on the light-emitting chip, and the light-emitting unit is electrically connected to at least one of the thin-film transistors.