LCD Visual Inspection Unit Bridge Line Static Dispersion
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Solution Overview
Problem
The challenge in liquid crystal displays with narrow bezels is the insufficient space for test pads and signal lines, leading to reduced tolerance margins during scribing and laser trimming, and increased static electricity issues during visual inspection.
Innovation Solution
The implementation of a visual inspection unit with a test pad and test lines connected via a bridge line, which allows for the transfer of common and storage electrode voltages, reducing the number of pads and minimizing static electricity by using indium tin oxide (ITO) or indium zinc oxide (IZO) bridge lines as a static electricity dispersion path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If test pads and signal lines are installed at the outside portion of the liquid crystal display, then visual inspection can be performed, but the space required increases and tolerance margin is reduced
Solution Approach 1:
The invention merges the test signal transmission function with the common electrode voltage transmission function by using the same test pad and test line for both purposes. The first test line transfers common electrode voltage Vcom and the second test line transfers storage electrode voltage Vcst, allowing dual functionality within the same inspection structure, thereby reducing the space required in the outside portion.
Solution Approach 2:
The test pad and test lines are designed to serve multiple functions: they can transmit test signals for visual inspection and simultaneously transmit common electrode voltage and storage electrode voltage. This multi-functionality reduces the need for separate dedicated structures, minimizing the space occupation in the outside portion of the display.
2Reliability
If test pads and signal lines are installed at the outside portion of the liquid crystal display, then visual inspection can be performed, but tolerance margin during scribing and laser trimming is reduced
Solution Approach 1:
By combining multiple functions into the same test pad and test line structure, the invention reduces the number of separate components required in the outside portion. This consolidation increases the effective tolerance margin during scribing and laser trimming operations, as there are fewer elements that require precise positioning and less cumulative tolerance accumulation.
3Reliability
If multiple test pads are used for visual inspection, then inspection capability is improved, but the number of pads increases and alignment difficulty increases
Solution Approach 1:
The invention merges the functions of multiple test pads into a single test pad that can transmit multiple test signals through different test lines. The first test line and second test line can transfer the same signal or different signals (Vcom and Vcst), eliminating the need for separate test pads for each signal type, thereby reducing pad count and simplifying alignment.
Solution Approach 2:
A single test pad is designed to be universal, capable of transmitting multiple types of test signals through its connected test lines. This multi-functional test pad reduces the total number of pads required while maintaining comprehensive inspection capability, and significantly reduces alignment complexity during assembly.
4Reliability
If traditional test structures are used, then visual inspection is possible, but static electricity inflow occurs during inspection
Solution Approach 1:
The invention introduces a bridge line as an intermediary element that connects the test pad to the second test line. This bridge line serves as a mediator that can be specifically designed with static electricity dispersion properties, allowing safe dissipation of static charges that accumulate during visual inspection, thereby protecting the display from static electricity damage.
Solution Approach 2:
The static electricity dispersion function is extracted as a separate, dedicated feature through the bridge line, which can be specifically engineered with materials and structures optimized for charge dissipation. This separates the static electricity management function from the signal transmission function, allowing each to be optimized independently.
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 solution enables a more compact liquid crystal display design with reduced static electricity and easier alignment of pads and jig pins during visual inspection, enhancing inspection efficiency and reliability.
Implementation Method 1
The bridge line may be made of indium tin oxide (ITO) or indium zinc oxide (IZO). The bridge line may be a static electricity dispersion line.
Data Source
AI summary
A liquid crystal display, including: a liquid crystal panel; and a visual inspection unit positioned in an outer region of the liquid crystal panel and transferring a test signal to the liquid crystal panel, in which the visual inspection unit includes: a test pad to which a test signal is applied; a first test line connected to the test pad; and a second test line connected to the test pad through a bridge line.