Display Device High-Melting Electrodes Sealant Heat Resistance
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Solution Overview
Problem
Conventional display devices with reduced bezel widths face challenges in sealing processes, where heat applied during sealing can damage the driving circuits and elements, particularly the transistors, due to the susceptibility of organic materials to high temperatures.
Innovation Solution
The display device design includes transistors with source and drain electrodes made of metals or metal alloys with a melting point greater than 700°C, such as molybdenum or aluminum-neodymium, and the elimination of organic insulating layers in the sealing region to prevent damage from heat, allowing for a reduced bezel width without compromising the integrity of the driving circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the bezel width is reduced, then the display area is increased, but the heat from sealing process damages the driving circuit
Solution Approach 1:
The source and drain electrodes of the second transistor are made with high melting point materials (molybdenum, aluminum-neodymium, or titanium nitride) specifically in the region affected by sealing heat, while other parts of the device can use different materials. This localized material selection allows the driving circuit to withstand the heat from the sealing process without compromising the overall device performance.
Solution Approach 2:
The melting point parameter of the electrode materials is changed from conventional low melting point materials to high melting point materials (≥700°C) for the source and drain electrodes of the second transistor. This parameter change enables the electrodes to withstand the high temperatures generated during the sealing process, preventing heat damage to the driving circuit.
2Reliability
If high melting point materials are used for source and drain electrodes, then heat resistance is improved, but manufacturing complexity increases
Solution Approach 1:
Instead of using high melting point materials throughout the entire device, the invention applies them only to the source and drain electrodes of the second transistor where heat resistance is critical. This localized approach maintains reliability where needed while minimizing the overall complexity of material selection and processing.
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 design effectively reduces the bezel width of the display device while protecting the driving circuits from heat-related damage during the sealing process, ensuring the reliability and efficiency of the organic light-emitting device.
Implementation Method 1
irradiating laser beams to the frit to melt the element substrate and the encapsulation substrate and bond them by a cured frit
Data Source
AI summary
A display device includes: a first substrate including a display area and a non-display area bordering at least a portion of the display area; a first transistor disposed in the display area, and includes a semiconductor layer, a gate electrode, a source electrode, and a drain electrode. A driving circuit is disposed in the non-display area, and includes a second transistor including a semiconductor layer, a gate electrode, a source electrode, and a drain electrode. An insulating layer disposed between the source and drain electrodes of the second transistor and the source and drain electrodes of the first transistor over the second transistor; a signal transmission line disposed in the non-display area, and transmitting a signal to the driving circuit; a second substrate facing the first substrate; and a sealant disposed in the non-display area between the first substrate and the second substrate, and overlapping the second transistor. The structure of the display device provides a bezel with a reduced width and resistance to pixel damage during formation of the sealant.