Display Device Low-Power Laser Welding for Defective Subpixel Darkening
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Solution Overview
Problem
Existing display devices face challenges in effectively darkening defective sub pixels and connecting them to normal pixel circuits, while minimizing damage to the welding area and reducing defects from static electricity.
Innovation Solution
A display device design that includes a first substrate with sub pixels, transistors, capacitors, and reflection plates, where capacitor electrodes are connected to gate and source electrodes in defective sub pixels, allowing for easy darkening and connection to normal pixel circuits using a low-power laser welding process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a high-power laser is used for welding to ensure strong bonding, then the welding strength is improved, but the damage to the periphery of the welding area increases
Solution Approach 1:
The patent applies local quality by using a low-power laser that concentrates energy precisely on the welding target area. The welding electrode is designed with specific geometric features (protrusion or hole structure) that localize the welding action to a small region, preventing heat diffusion to surrounding areas. This allows strong welding at the contact point while minimizing peripheral damage.
Solution Approach 2:
The welding electrode serves as an intermediary between the laser energy source and the welding target. It mediates the energy transfer by concentrating the laser energy at its tip or contact point, achieving effective welding with low overall power input. The electrode structure (protrusion or hole) acts as the intermediary that enables precise energy localization.
2Reliability
If multiple welding processes are used to darken defective sub pixels, then the darkening effect is achieved, but the manufacturing complexity increases
Solution Approach 1:
The patent merges the darkening function into a single welding process step. By designing the welding electrode with specific geometric features (protrusion or hole) and positioning it to contact multiple capacitor electrodes simultaneously, the welding operation achieves both electrical connection and darkening of the defective sub pixel in one action, eliminating the need for separate darkening processes.
Solution Approach 2:
The welding electrode is designed with multi-functionality, serving both as the welding tool for electrical connection and as the darkening mechanism for defective pixels. The same welding structure that provides electrical contact also creates the darkening effect through its geometric design, allowing one component to perform multiple functions.
3Reliability
If reflection plates are connected using conventional welding, then the electrical connection is established, but defects from static electricity occur
Solution Approach 1:
The welding electrode acts as an intermediary that enables static-free connection of reflection plates. By using the electrode's protrusion or hole structure to create controlled contact points, the welding process establishes electrical connection without generating static electricity defects that would occur with conventional welding methods.
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 design enables efficient darkening of defective sub pixels through two welding processes, reduces peripheral damage, and minimizes defects from static electricity, simplifying the repair process and maintaining display quality.
Implementation Method 1
allowing for easy darkening and connection to normal pixel circuits using a low-power laser welding process
Data Source
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Figure 2B
AI summary
According to an aspect of the present disclosure, a display device includes a first substrate in which a plurality of sub pixels including at least one defective sub pixel and a plurality of normal sub pixels is defined; a light emitting diode which is disposed in each of the plurality of sub pixels; a driving transistor having a source electrode connected to a first electrode of the light emitting diode; and a capacitor which includes a plurality of capacitor electrodes connected to a gate electrode and the source electrode of the driving transistor. The plurality of capacitor electrodes is in contact with each other in the defective sub pixel. Accordingly, in the defective sub pixel, the capacitor electrodes are connected to each other to connect the gate electrode and the source electrode of the driving transistor and the defective sub pixel may be easily darkened.