Display Pad Inspection Using Alternating-Polarity Buffer Currents
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Solution Overview
Problem
Existing display devices face challenges in efficiently detecting short defects between pads during the manufacturing process, which affects the quality reliability of the display devices.
Innovation Solution
The display device incorporates a driving chip with buffers configured to output data signals of alternating polarities through separate buffer lines, allowing for the measurement of buffer currents to detect short defects between pads, and a method to inspect the device by providing buffer voltage, outputting data signals, and measuring buffer currents to determine defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inspection methods are used to detect short defects between pads, then the inspection process becomes complex and time-consuming, but the defect detection accuracy is insufficient
Solution Approach 1:
The patent changes the inspection parameter from visual or electrical resistance measurement to current measurement under alternating polarity conditions. By applying different polarities to adjacent pads and measuring the buffer current, the system can detect short defects through current magnitude changes, achieving high detection accuracy with a relatively simple current measurement setup
Solution Approach 2:
The patent replaces complex multi-step inspection procedures with a simplified electrical measurement system. Instead of using complex imaging or multiple measurement devices, the system uses a single current measurement approach with polarity switching to detect defects, reducing inspection complexity while maintaining or improving detection accuracy
2Reliability
If conventional inspection methods are used to detect short defects between pads, then the inspection time is extended, but the defect detection capability is limited
Solution Approach 1:
The patent employs periodic action by alternating the polarity of the buffer voltage applied to adjacent pads. This periodic polarity switching enables the detection of short defects between different pad pairs in sequence, allowing comprehensive inspection of all pad connections to be completed through repeated cycles of voltage application and current measurement, thereby improving reliability without significantly extending inspection time
Solution Approach 2:
The patent performs preliminary action by applying buffer voltage to the pads before actual measurement. This preliminary voltage application ensures that the pads are properly biased and any short defects are already established in the circuit path, allowing for more accurate and faster detection during the subsequent current measurement phase
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 accurate detection of short defects between pads, enhancing the quality reliability of the display device by identifying potential defects effectively.
Implementation Method 1
buffers configured to receive a buffer voltage through a buffer line that is different from the input line, and output the data signals to the pads
Data Source
AI summary
A display device includes: a display panel configured to display an image corresponding to an image signal, and including pads; and a driving chip configured to provide data signals to the pads. The driving chip includes: an analog part configured to convert an input voltage received through an input line into a driving voltage, and convert an image data signal into the data signals; and buffers configured to receive a buffer voltage through a buffer line that is different from the input line, and output the data signals to the pads.