Leakage Detection in Matrix-Structured OLED Pixels
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Solution Overview
Problem
Existing OLED displays face challenges in detecting and measuring small leakage currents in pixels, which can lead to pixel shorts, making it difficult to identify potentially faulty pixels before they develop into shorts, especially in high-density matrix-structured devices.
Innovation Solution
A high-throughput screening technique that involves applying specific voltages to anode and cathode lines, measuring voltages across elements, and using techniques such as voltage comparison and differential voltage analysis to identify leaky elements, either electrically or visually, to quickly detect pixels with high leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement methods are used to detect pixel leakage current, then measurement precision can be maintained, but productivity deteriorates due to time-consuming measurements
Solution Approach 1:
The display device is divided into multiple groups, with each group containing multiple pixels. Instead of measuring each pixel individually, the method measures the combined current of multiple pixels in parallel, significantly reducing the number of measurements required while maintaining detection capability for high leakage currents
Solution Approach 2:
Multiple pixel measurements are merged into a single group measurement. By connecting multiple pixels in parallel within each group and measuring them simultaneously, the method achieves high-throughput screening without sacrificing the ability to identify pixels with excessive leakage currents
2Measurement precision
If each pixel is measured individually for accurate leakage detection, then measurement precision is improved, but device complexity increases due to the large number of pixels
Solution Approach 1:
The display device is divided into multiple groups, with each group containing multiple pixels. Instead of measuring each pixel individually, the method measures the combined current of multiple pixels in parallel, significantly reducing the number of measurements required while maintaining detection capability for high leakage currents
Solution Approach 2:
The measurement method is designed to be universally applicable to any pixel within a group. The same measurement procedure and criteria can be applied across all groups and all pixels, simplifying the measurement system design and operation while handling large-scale displays
Data Source
AI summary
One embodiment of this invention pertains to a high throughput screening technique to identify current leakage in matrix-structured electronic devices. Because elements that are likely to develop a short have relatively high leakage current at zero operation hours, by identifying elements with the relatively high leakage current, the electronic devices that are more likely to later develop a short can be differentiated. The screening technique includes performing the following actions: selecting one of multiple first lines; applying a first voltage to the selected first line; applying a second voltage to the one or more of the first lines that are not selected; floating the multiple second lines; and measuring the voltages on the second lines, either sequentially one line at a time or measuring all the lines at the same time.