Laser Repair of Flat Panel Display Defects
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Solution Overview
Problem
Existing methods for repairing defective pixels in LCDs during manufacturing are incomplete, as light leakage occurs from the lateral side rather than the front, making it difficult to achieve a complete repair.
Innovation Solution
A laser-based repair method using a laser with a selected wavelength (750-850 nm or 1000-1100 nm) and pulse width (femtoseconds to picoseconds) is applied to focus on signal lines and color filters, allowing for effective repair by changing the transmittance of color filters and absorbing light from the light source unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a light-shielding film is formed on the display panel to cover the defective pixel region, then the light leakage from the front side is blocked, but light still leaks from the lateral side making the repair incomplete
Solution Approach 1:
The patent transitions from a two-dimensional surface repair approach (light-shielding film on the front surface) to a three-dimensional volumetric repair approach by injecting repair material into the lateral side and depth of the defective pixel region through side injection holes. This multi-dimensional approach blocks light leakage paths that the surface film alone cannot address.
Solution Approach 2:
The patent introduces a repair material as an intermediary substance that is injected into the defective pixel region. This repair material serves as a mediator between the defective pixel and the external environment, filling voids and blocking light leakage paths from both the front and lateral sides.
2Adaptability or versatility
If multiple repair devices and methods are used to address different types of defects, then various defect types can be repaired, but the device complexity and manufacturing process become more complex
Solution Approach 1:
The patent develops a universal repair apparatus that can handle multiple defect types (high pixels, dark pixels, foreign objects, wiring defects) through a single integrated system. The apparatus uses a common side injection mechanism that can deliver different repair materials or treat different regions, eliminating the need for multiple specialized repair devices.
Solution Approach 2:
The patent enables versatile defect repair by changing parameters of the repair process rather than using different devices. By adjusting injection pressure, repair material properties, injection hole positions, and laser parameters, the same apparatus can effectively treat various defect types, reducing device complexity while maintaining adaptability.
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 approach enables complete and effective repair of defective pixels by ensuring light absorption, minimizing collateral damage, and allowing for repair during various testing stages without the need for multiple devices.
Implementation Method 1
a laser that radiates laser light having a selected wavelength and a pulse width of from femtoseconds (10−15 seconds) to picoseconds (10−12 seconds)
Implementation Method 2
changing the transmittance of color filters and absorbing light from the light source unit
Data Source
AI summary
Apparatus and methods for repairing display devices of a type that include a first substrate having a plurality of signal lines formed thereon and/or a second substrate having a plurality of color filters formed thereon include a laser that radiates laser light having a wavelength in a range of from about 750 to about 850 nm, or alternatively, of from about 1000 to about 1100 nm, and a pulse width of femtoseconds (10−15 seconds) to picoseconds (10−12 seconds) and arranged such that the laser light can be focused on selected ones of the signal lines and/or color filters. The apparatus enables repairs to be effected on the display device during any one of several manufacturing test processes using only a single laser apparatus, without the need for additional or different repair devices for each test process.