Inspection Pad Reduction via Switch Element Signal Sharing

Solution Overview

Problem

In downsized liquid crystal display panels, especially for mobile phones and smartphones, the limited area available for arranging inspection pad electrodes becomes a challenge when multiple control signals need to be input, leading to difficulties in ensuring sufficient space and increased complexity in inspection processes.

Innovation Solution

The solution involves forming a display device with a first substrate that includes a plurality of signal lines and inspection pads, where a switch element, such as a thin film transistor, is used to share control signals between adjacent signal lines, reducing the number of inspection pads required by using a gate voltage pad to control the switch element and dividing signal lines under the inspection pads to enable efficient signal input during inspection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If the number of inspection pad electrodes is reduced to fit limited area, then the area utilization is improved, but the probing precision deteriorates

Engineering Contradiction:

Improvearea for inspection pad electrodesVSAvoidprobing precision

Core Design Contradiction:

Area of stationary objectVSMeasurement precision

Solution Approach 1:

Multiple inspection pad electrodes are merged into a single shared inspection pad by using switch elements to selectively connect different signal lines to the same pad during different inspection phases, allowing one pad to serve multiple functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inspection pad configuration is made dynamic through switch elements that can change connections between signal lines and the inspection pad based on inspection requirements, allowing the same physical pad to represent different signal lines at different times

Inventive Principle:

Principle #15Dynamics

2Area of stationary object

If the pitch between inspection pad electrodes is reduced to fit limited area, then the area utilization is improved, but the inspection throughput deteriorates

Engineering Contradiction:

Improvearea for inspection pad electrodesVSAvoidinspection throughput

Core Design Contradiction:

Area of stationary objectVSProductivity

Solution Approach 1:

Multiple inspection pad electrodes are merged into a single shared inspection pad by using switch elements to selectively connect different signal lines to the same pad during different inspection phases, allowing one pad to serve multiple functions

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inspection pad configuration is made dynamic through switch elements that can change connections between signal lines and the inspection pad based on inspection requirements, allowing the same physical pad to represent different signal lines at different times

Inventive Principle:

Principle #15Dynamics

3Reliability

If multiple control signals are input to the integrated circuit during inspection, then the inspection completeness is improved, but the device complexity increases

Engineering Contradiction:

Improveinspection completenessVSAvoidcomplexity of inspection pad arrangement

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

A single inspection pad is designed to perform multiple functions by being dynamically connected to different signal lines through switch elements, allowing one pad to input multiple different control signals during different inspection phases

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The inspection pad configuration is made dynamic through switch elements that can change connections between signal lines and the inspection pad based on inspection requirements, allowing the same physical pad to represent different signal lines at different times

Inventive Principle:

Principle #15Dynamics

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 effectively reduces the number of inspection pads needed, improving inspection throughput and reducing costs by simplifying the inspection process while maintaining precision, even when multiple control signals are required.

Implementation Method 1

the second signal line is connected to the inspection pad through a switch element, and at the time of inspection, the switch element turns on

Methodology Applied

Scientific EffectSwitch element conduction control:

Data Source

PatentUS9046725B2Display device

Publication Date: 2015.06.02 MAGNOLIA WHITE CORP

AI summary

Inspection pads are reduced when there is a need to input a plurality of control signals as inspection control signals. A display device includes: an integrated circuit; a first substrate on which a plurality of signal lines that respectively input the control signals to the integrated circuit, and an inspection pad are formed; and a driver circuit that that is mounted on the first substrate and connected to the plurality of signal lines. The plurality of signal lines include first and second signal lines adjacent to each other. The inspection pad is formed on the one signal line. The second signal line is connected to the inspection pad through a switch element. At the time of inspection, the switch element turns on, and the same control signal is input to the first and second signal lines from the inspection pad.